Thursday
Dec292011

Flight Nutrition Guidelines

Gary Slater/ Michelle Cort Sports Dietitians Australian Institute of Sport

Website: Australian Rowing website


Nutrition and Hydration Strategies for Long Haul Flights

To reduce the interference that long haul flights can have on performance the first few days after arrival, it is important to ensure you have appropriate nutrition and hydration strategies in place before, during and immediately after the flight.

Meals and Snacks:

• In addition to adjusting your sleep patterns to coincide with those of your destination in the days prior to departure, try to adopt the meal pattern you will have at your destination. This will help reduce jet lag and adjust your body clock.
• Rowers with reduced energy needs (e.g. those attempting to make weight or on ‘low energy budgets’) may not need all the meals and snacks provided during flights. Drinking low energy fluids (water, tea, diet soft drinks) and chewing sugar free gum can decrease the temptation to snack excessively during flights. Alternatively pack your own lower energy snacks like fresh fruit and decline some of the high energy/ high fat in-flight snacks.
• Rowers with high fuel needs should pack extra snacks to supplement the food provided in-flight to ensure weight loss and a decrease in fuel stores does not occur. Good snack choices include cereal bars, sports bars, powdered liquid meal supplements (plus a shaker), plus dried fruit and nut mixes.

Hydration Strategies:

• The risk of becoming dehydrated on long flights is increased as the pressurised cabin and air-conditioned environment increases fluid losses from the skin and lungs. The small fluid serve sizes available on flights are usually insufficient to maintain hydration.
• Purchase extra fluids after clearing security to add to your carry on luggage.
• Aim for approximately 1 cup per hour to maintain hydration.
• Suitable choices include: water, sports drink, juice, soft drink, tea and coffee.
• Sodium assists in decreasing urine losses (and thus promoting improved hydration). Sports drinks contain a small amount of sodium that can be useful. Other electrolyte rich solutions (e.g. Gastrolyte in water or Gatorlytes added a sports drink) can also be valuable, especially for those who struggle to remain well hydrated.
• Once at your destination rapid re-hydration should be a priority. Continue to drink regularly. Adding Gastrolyte to water (10 tablets or 5 sachets in 1L of water) on arrival can help promote faster re-hydration.

New Rules for International Flights:

To enhance flight safety the federal government has enforced new rules about taking liquids, aerosols and gels on flights into and out of Australia. In brief, each container of liquid, aerosols or gels in carry-on luggage AT THE SECURITY SCREENING POINT (but not when you board the plane) must be less than 100 ml.

By following the guidelines below, this should have no impact on your in-flight hydration strategies.

• Carry an empty drink bottle through the security screening point, filling your drink bottle up at a bubbler on the other side of the screening point.
• Purchase drinks (including water, sports drinks, juices, etc) at shops on transit to your departure gate.
• Include powdered sports drinks, powdered liquid meal supplements (e.g. Power Bar Protein Plus, Sustagen Sport) and perhaps sachets/tablets of oral rehydration salts (Gastrolyte, Gatorlytes) in your carry on luggage that can be made up (on water) in your drink bottle or shaker for the flight.

For more information on these new travel regulations, check out the Australian Government Department of

Transport and Regional Services information sheet at: 

Australia - page 2.

Great Britain and Europe

USA

Sunday
Dec182011

Nutrition Strategies for Rowing

Written by the Department of Sports Nutrition, AIS 2006
Australian Sports Commission 2006

For a print copy: Nutrition Strategies for Rowing


Training Nutrition:

Rowing requires a unique mix of technique, power and endurance, utilising both the anaerobic and aerobic energy systems. Rowers have very high energy and carbohydrate requirements to support training loads and meet body weight and strength goals.

Some rowers (particularly male heavyweights) struggle with the shear volume of food they need to consume to meet their training demands. Frequent snacks and the use of compact, energy dense food or drinks such as juice, flavoured milk, jam, honey, sports bars and liquid meals are necessary to keep the volume of food manageable.

Nutrition recovery strategies between sessions are extremely important and the rower must have a planned approach to their training nutrition.

Carbohydrate: How much?

Carbohydrate is a critical fuel source for the muscle and central nervous system. Carbohydrate intake before, during and after exercise can be required to meet the fuel requirements of the activity.

A rower can calculate a carbohydrate target in grams, and use food tables or information on food labels to plan to meet this goal. Even better, a rower can see a Sports Dietitian for advice to further narrow this target range according to his/her specific situation, and have an individualised meal plan fitted to their needs.

Situation

Recommended Carbohydrate Intake

Daily refuelling needs for training programs less than 60-90mins per day or low intensity exercise

Daily intake of 5-7g per kg body mass.

Daily refuelling for training programs greater than 90-120 min per day

Daily intake of 7-10g per kg body mass.

Daily refuelling for athletes undertaking extreme exercise program: 6-8 hours per day

Daily intake of 10-12+ g per kg body mass.

Pre-event meal

Meal eaten 1-4 hrs pre-competition 1-4g per kg body mass.

Carbohydrate intake during training sessions and competition events greater than 1 hour

1g per minute, or 60g per hour

Rapid Recovery after training session or multi event competition, especially when there is less than 8 hrs until the next session

Intake of 1g per kg body mass in the first 30 min after exercise, repeated every 1-2 hrs until regular meal patterns are resumed

 

A chart that provides information about the carbohydrate content of common foods can be viewed on (www.ais.org.au/nutrition). You can use this information to plan a daily menu, or specific pre-competition meals and post exercise snacks and meals.

Protein:

Rowers in heavy training require extra protein to cover a small proportion of their energy costs of their training and to assist in the repair and recovery process after exercise. Adolescent rower’s who are still growing, have additional protein requirements.

Protein Requirements can be summarised as follows:

Situation

Grams protein per kg body mass per day

Light training program

1.0

Moderate to heavy training

1.2-1.7

Adolescent Rowers

2.0

 

Which foods are the best to provide protein?

The following table indicates the protein content of many foods. Each of the foods provides approximately 10g of protein.

Animal Foods

Plant Foods

2 small eggs

30g (1.5 slices) reduced fat cheese

70g cottage cheese

1 cup (250ml) low fat milk

35g lean beef, lamb or pork (cooked weight)

40g chicken (cooked weight)

50g grilled fish

50g canned tuna or salmon

200g reduced fat yoghurt

150g light fromage frais

4 slices (120g) bread

3 cups (90g) wholegrain cereal

2 cups (330g) cooked pasta

3 cups (400g) cooked rice

¾ cup (150g) lentils or kidney beans

200g baked beans

120g tofu

400ml soy beverage

60g nuts or seeds

1 cup (250ml) soy milk

100g soy ‘meat’

 

Are high protein low carbohydrate diets appropriate for Rowers?

In the short term high protein, low carbohydrate diets result in loss of water and glycogen. This might result in a decrease on the scales, but does nothing to reduce body fat. In the long term high protein, low carbohydrate diets may result in fat loss. The effect is primarily due to the fact that these diets are low in kilojoules rather than any magical effect from the protein itself. The lack of carbohydrate reduces energy levels, impairs performance and causes lethargy and nausea. High protein, low carbohydrate diets restrict the intake of many nutrients in the diet. These diets will result in muscle mass decrease. High protein, low carbohydrate diets are not suitable for athletes.

Weight Loss:

In lightweight rowing the need to maintain low levels of body fat is important. Rowers needing to reduce skinfolds must target excess kilojoules in their diet. In particular, excess fat, alcohol and sugary foods should be targeted and replaced with more nutrient dense choices (see the AIS Sports Nutrition Fact Sheet: “Weight Loss” www.ais.org/nutrition for more detailed information)

Muscle Mass Gain:

Specific information relating to nutrition strategies for lean muscle mass gain can be found in the AIS Sports Nutrition Fact Sheet: “How to Grow Muscles” (www.ais.org.au/nutrition).

Pre Exercise Nutrition:

Depletion of carbohydrate stores is a major cause of fatigue during exercise.

Eating Before Early Morning Sessions:

After an overnight fast (sleeping) liver glycogen (energy) stores are substantially depleted. Therefore, pre training carbohydrate intake is important for maintaining blood glucose levels towards the end of prolonged training sessions.

Example: some fruit and a cereal bar on the way to training along with some fluid such as a sports drink would be a good choice. If tolerating solid food before training is difficult a liquid meal alternative such as Protein Plus drink or a smoothie or even a glass of juice can be useful in providing essential carbohydrate.

Making up for the smaller carbohydrate intake before exercise by consuming carbohydrate during the training session (eg: sports drink) is an important strategy. The rower should experiment to find a routine that works and is comfortable for them.

Other Exercise Sessions:

Food eaten before training should contain carbohydrate. It should also be low in fat and fibre to aid in digestion and reduce the risk of gastrointestinal discomfort or upsets.  Fluid needs should also be considered.

Further detailed information on pre exercise eating can be accessed on www.ais.org.au/nutrition in the AIS “Eating Before Exercise” fact sheet.

Recovery Nutrition Strategies:

Recovery is a challenge for rowers who are undertaking two or more sessions each day, training for long periods, or competing in a program that involves multiple races. Between each workout the body has to adapt to the physiological stress. In training, with correct planning of the workload and the recovery time, adaptation allows the body to become fitter, stronger and faster. In competition however, there may be less control over the work to recovery ratio.

Nutrition recovery strategies encompass a complex range of processes that include:
• restoring the muscles and liver with expended fuel (glycogen)
• replacing the fluid and electrolytes lost in sweat
• allowing the immune system to handle the damage and challenges caused by the exercise bout.
• Manufacturing new muscle protein, red blood cells and other cellular components as part of repair and adaptation processes

The importance of each of these goals varies according to the workout. A pro-active recovery means providing the body with all the nutrients it needs, in a speedy and practical manner, to optimise the desired processes following each session.

Refuelling:
To kick start the refuelling process an intake of at least 1g/kg of carbohydrate (50-100g) for most athletes is needed. Athletes should consume this carbohydrate -in their next meal or snack- as soon as possible after a heavy session to prepare for the next.

Rehydration:
Most athletes finish a training or competition session with some level of fluid deficit. Comparing pre and post exercise measurements of  body weight can provide an approximation of the overall fluid deficit. Athletes may need to replace 150% of the fluid deficit to get back to baseline.

Immune System:
The immune system is suppressed by intensive training. This may place athletes at risk of succumbing to an infectious illness during this time. Consuming carbohydrate during and/or after a prolonged or high intensity work out has been shown to reduce the disturbance to immune system markers.

Muscle Repair and Building:
Prolonged and high intensity exercise causes a substantial breakdown of muscle protein. During the recovery phase there is a reduction in catabolic (breakdown) processes and a gradual increase in anabolic (building processes). Early intake of good quality protein foods helps to promote the increase in protein rebuilding. Protein consumed immediately after the session (or in the case of resistance training sessions, immediately before the session), is taken up more effectively by the muscle into rebuilding processes, than protein consumed in the hours afterwards.

However the protein needs to be consumed with carbohydrate foods to maximise this effect. Carbohydrate intake stimulates an insulin response, which potentiates the increase in protein uptake and rebuilding.

Nutritious Carbohydrate – Protein Recovery Snacks (contain 50g carbohydrate + valuable source of protein):

- 250-300ml liquid meal supplement (eg: Protein Plus Drink)
- 250-300ml milkshake or fruit smoothie
- 1-2 sports bars (check labels for carbohydrate and protein content)
- 1 large bowl (2 cups) breakfast cereal with milk
- 1 large or 2 small cereal bars + 200g fruit flavoured yoghurt
- 1 bread roll with cheese/meat filling + banana
- 300g (bowl) fruit salad with 200g fruit flavoured yoghurt
- 2 x crumpets with peanut butter and 200ml falvoured milk

Hydration Strategies:

Drinking regularly during exercise, athletes can prevent the negative effects associated with dehydration and performance can be improved. Every rower should make fluid replacement a key priority during training and competition. Long training sessions on the water lead to significant sweat losses.

The table below shows sweat losses and fluid intakes recorded on AIS rowers in different environmental conditions. Despite having drink bottles available, athletes failed to consume enough fluid to keep up with their sweat losses, particularly in hot weather. Note however, that even in cold weather considerable sweat losses were seen.

Session

Season

Sweat losses men

(ml/hr) (range)

Fluid intake men

(mlhr) (range)

Sweat losses women (ml/hr) (range)

Fluid intake, women (mlhr) (range)

Training

Hot conditions 320C

1980

(990-2150)

960

(410-1490)

1390

(740-2335)

780

(290-1390)

Training

Cool conditions 100C

1165

(430-2000)

582

(215-1265)

780 (360-1550)

405

(145-660)

 

Dehydration impairs the body’s ability to regulate heat resulting in increased body temperature and an elevated heart rate. Associated negative effects include: increased perceived exertion, reduced mental function (decreased motor control, decision making and concentration). Gastric emptying is also slowed, resulting in stomach discomfort. All of these effects lead to an impairment in exercise performance. The negative effects of dehydration on performance are exacerbated further in hot conditions.

Fluid requirements vary markedly between rowers and in different exercise sessions. It is impossible to prescribe a general fluid replacement plan that will meet the needs of all rowers. Rowers can estimate their own fluid requirements by weighing themselves pre and post exercise sessions. Each kilogram lost is approximately equivalent to 1 litre of fluid. Once a rower’s individual sweat losses are known, a plan can be prepared to help him/her to achieve better fluid replacement in following exercise sessions.

Where possible it is better to begin drinking early in exercise and adopt a pattern of drinking small volumes regularly rather than trying to tolerate larger volumes in one hit.

What to Drink?
Research shows that fluid intake is enhanced when beverages are cool (~ 150C), flavoured and contain sodium. This makes sports drinks an ideal choice during exercise. In addition to replacing fluid and electrolytes lost through sweat, sports drink also contains carbohydrate which allows re-fuelling to take place during exercise.

Water is still a suitable option during exercise. However water drinkers need to be aware that water does not stimulate fluid intake to the same extent as sports drinks. Drinking to a plan is therefore crucial when drinking water. Don’t rely on thirst.

Cordial, soft drinks and juice generally contain greater than 10% carbohydrate and are low in sodium. This can slow gastric emptying and makes these drinks a less suitable choice, especially for high intensity activity.

Other Useful Hydration Strategies:

• Drink with all meals and snacks. Consume 300-400ml of fluid in the hour before training commences to ensure you begin each session hydrated.
• Take sufficient drink bottles to training. Keep some in the coaches boat for top ups.
• Take a few seconds every 15-20mins or between pieces for a drink break. Alternatively, try using a drink container like a hydration-pack, which is worn on the back, to avoid having to take your hands off the oar to drink.
• Re-hydrate fully after the session.
• Sports drinks are the recommended fluid choice during rowing.
• Lightweight rowers should not consider a lower weight at the end of a workout to be a good sign. Even though dehydration is an inevitable part of making weight for competition, it is counterproductive and unnecessary in the training setting.

Competition Nutrition:

Rowers should go into each race with fluid and fuel stores topped up, and feeling comfortable after their last meal. With the regatta or competition lasting a number of days, the challenge is to recover between each day’s sessions and to prepare for the next race (see Recovery Nutrition Strategies section above).

Generally a meal that provides carbohydrate should be consumed 2-3 hours before a race, eg: breakfast cereal, toast, muffins, sandwiches, yoghurt, fruit, pasta and creamed rice. Some rowers need to take special care with pre race eating, as it can be very uncomfortable to race with a full stomach. Low bulk choices such as liquid meals and sports bars can be useful in these situations.

Rowers need to organise themselves to have appropriate food and fluids available at all times during competition. Many athletes find that they easily lose weight over the course of a competition due to being unable to consume their usual high energy diet (as they are spending much of the day in preparation and the race itself) To help avoid this from happening take along a supply of cereal bars, liquid meal supplements sports bars, fruit bars, dried fruit, sandwiches, yoghurt, juice etc…

Be aware of your fluid needs (see Hydration Strategies section above). You can be dehydrated from your rowing efforts, making weight practices or just from sitting in the sum watching competition.

Supplements:

While a lot of sports foods and supplements do not live up to their emotive claims, some of these products are valuable in helping an athlete achieve their nutritional goals and optimal performance. State of the art information on Sports Foods and Supplements can be found in the AIS Sports Supplement Program information and the AIS “Supplements in Sport – Why are they so tempting?” fact sheet, which are both located at: www.ais.org.au/nutrition.

Some sports foods and dietary supplements play a role in providing a practical alternative to food (eg: sports drinks, sports gels, sports bars, and liquid meal supplements). Rowers may find these products valuable in helping them achieve their nutrition goals in a busy day or during an exercise session. They are an alternative to every day foods, which might need to be combined and juggled to produce the same nutritional composition, or which might be too impractical to consume directly before or during intense exercise. Sometimes the convenience factor is the selling point.

Some rowers however use these products outside the conditions in which they are likely to achieve a direct sport nutrition goal (eg: eating sports bars as a snack). In these situations sports foods may simply be a more expensive version of food. Over-consumption of any sports foods can lead to dietary imbalances as well as being an unnecessary burden on the wallet. Specific sports nutrition advice from a Sports Dietitian will make the rower aware of the best uses of these special sports foods.

Sports Dietitians:

While this information provides a good general overview to sports nutrition for rowing, a more individualised nutrition plan will help to maximise your rowing performance. Your State Institute or Academy will have the expertise to help you. Additionally Sports Dietitians Australia (http://www.sportsdietitians.com.au/) has a list of accredited Sports Dietitians throughout Australia that can provide you with this service.

 

 

Wednesday
Dec142011

Mathematician Solves Rowing Boat "Wiggle" Problem

By: John D. Barrow 

(Submitted on 18 Nov 2009 (v1), last revised 16 Aug 2010 (this version, v3))

Website: Technology Review


Abstract

We consider the optimal positioning of an even number of crew members in a coxless racing boat in order to avoid the presence of a sideways wiggle as the boat is propelled forwards through the water. We show that the traditional (alternate port and starboard) rig of racing boats always possesses an oscillating non-zero transverse moment and associated wiggling motion. We show that the problem of finding the zero-moment rigs is related to a special case of the Subset Sum problem. We find the one (known) zero-moment rig for a racing Four and show there are four possible such rigs for a racing Eight, of which only two (the so called 'Italian' and 'German' rigs) appear to be already known. We also give the 29 zero-moment solutions for racing Twelves but refrain from explicitly listing the 263 Sixteens and 2724 Twenties which have zero transverse moments. We show that only balanced boats with crew numbers that are divisible by four can have the zero-moment property. We also discuss some aspects of unbalanced boats, in which the number of port and starboard oars are unequal. 

A mathematician has discovered two entirely new arrangements of rowers in a racing eight in which the rowing forces cancel to make the boat wiggle-free.

kfc 11/20/2009

They take their rowing seriously at the University of Cambridge. So seriously, in fact, that the university has press-ganged John Barrow at the Center for Mathematical Sciences to study the serious problem of oscillating non-zero transverse moment in racing boats, otherwise known as wiggle.
 
The placement of the rowers, the "rig" of the boat, obviously has consequences for the motion of the boat. The question is how best to arrange an even number of crew members in a coxless racing boat in a way that minimizes or eliminates wiggle.
 
The traditional way of rigging a boat places rowers alternately pulling oars on each side of the boat. "The traditional rig appears symmetrical and simple in ways that might tempt you into thinking it is in every sense optimal. However, this is not the case," says Barrow who goes on to show that the balance of forces in this rig as the oars are pulled through the water always produces a wiggle.
 
But there is an arrangement in which the transverse forces cancel. This rig consists of one rower pulling on the port side of the boat followed by two on the starboard with a final rower on port. In the rowing world, this arrangement is known as the Italian rig because it was discovered by the Moto Guzzi Club team on Lake Como in 1956. The Moto Guzzi crew went on to win gold representing Italy at the Melbourne Olympic Games later that year.
 
Barrow next considers a crew of eight and identifies four possible rigs that have a zero transverse moment. These are shown above. The interesting thing is that only two of these rigs are known to the racing world. Rig b is called the "bucket," or "Ratzeburg rig," first used by crews training at the famous German rowing club of the same name in the late 1950s.

Rig c is simply the Italian rig repeated twice. It was used by the Italian Eights in the 1950s after their success with the Fours. It's also known as the triple tandem rig.

The other two, rigs a and d, are brand spanking new and don't seem to have ever been discussed. However, Rig d is a combination of a zero-moment Italian Four with its mirror image.
 
Barrow goes on to generalize the idea for any number of crew, proving along the way that only crew numbers divisible by four can be wiggle-free. (Assuming that they are evenly spaced.)

He also goes on to show that unbalanced boats in which there are unequal numbers of oars on each side, can also be wiggle free if the spacing between the rowers can be altered. As an example, he shows how a Three could have a zero transverse moment.
 
Barrow ends by saying that his work is not intended to revolutionize rowing tactics. That seems overly modest. Clearly, Barrow's paper should be recognized as a master stroke.
 
Will we see at least one of the new rigs at the 2012 Olympics in London?

Ref: arxiv.org/abs/0911.3551: Rowing and the Same-Sum Problem Have Their Moments. 

TRSF: Read the Best New Science Fiction inspired by today’s emerging technologies.


Monday
Dec122011

The 2000m ergometer test

By: Walter Martindale, M.P.E., ChPC
New Zealand Coach Development Manager

For a print copy: The 2000m Ergometer Test


Introduction

Some suggestions for coaching athletes to a best performance. Unfortunately, to be thorough, this gets a bit long… The “basics” of getting a great ergometer test are in “bold” font, like this. The rest of the document provides a “not quite layman’s” description of the “why” behind the basics.

Recent observations of 2000 m ergometer tests have prompted a selector to ask that club and school coaches learn how to prepare an athlete to take an ergometer test. We saw some very heroic starts, followed by struggles to survive.

So – to that end – a primer on taking an ergometer test, with some of the physiology about why these suggestions should help. It’s directed mostly at the athlete, but coaches can relay this information, or just stick to the basics. This is NOT the only way to “take” an ergometer test, but it’s an approach that’s based on physiology, some experience, and some observations.

First, let’s talk about the common statement that ergometers don’t float. Of course they don’t float.

That’s not what the ergometer test is about. People who make boats move fast almost always have good ergometer scores – people who have good ergometer scores don’t necessarily make boats move fast. With good technique, they can move a boat fast, but with bad technique, they won’t go as fast as someone who doesn’t quite pull as hard but has good technique. If you aim to have both good technique and a good erg score, you’ll have a better chance to be the fastest in a boat. The ergometer test is simply a snapshot of your physical fitness and toughness, and can tell a coach or a selector a lot about you. The monitor on an ergometer tells the truth – no matter how hard you think you’re pulling, the numbers show you just how effective the efforts are being. After the ergometer test, if you are going through a selection process, no matter at what level, you start off on a better footing if you have cranked out a big ergo score. When you’re training on an ergometer, the more closely you can approximate good technique on the ergometer, the more beneficial carry-over you’ll have to the boat.

The ergometer test is just like the A final of a big regatta

People need to warm up adequately, run a “race plan” and afterwards do a proper “row down.”

Basic Physiology for coaches and athletes

Some basic physiology that explains why a good warm-up is important. Biochemists and physiology researchers beware: this is phrased so that non-physiology people can get it. If the following description is badly flawed, I’d like a physiologist to let me know so I can fix it. If the description is a good “glossing over” of what happens, but not complete, I’d like that confirmed. The description is “AIUI” or As I Understand It, from tertiary courses in exercise physiology from the 80s and Level 4 coaching courses in the 90s.

There are three main “energy supply systems” in your muscles. These are called various names by various physiology people, but what will be used in this paper is: “Anaerobic Alactic”, “Anaerobic Lactic” and “Aerobic.” The names are based on the chemistry that goes on in the muscle cells, and this naming system is just one. Some characteristics of these systems will be outlined below.

There’s a whole lot of physiology that goes on when a muscle contracts, from the person deciding to move, to the brain deciding which muscles to use, through the nerves to the muscles which get a signal to contract. There is a lot of “stuff” that is still being researched about muscle physiology, but the overall process is relatively well documented. The details are far beyond the scope of this paper (and my knowledge).

The “action” chemical in a muscle is called ATP (Adenosine TriPhosphate). Essentially, the ATP, by splitting off one of the phosphates to become Adenosine DiPhosphate+Phosphate+energy (ADP+P+energy), and giving the energy from that split to the muscle fibre, makes the muscle fibre “pull,” making the body move. A resting muscle carries enough ATP for about 4-5 seconds of full-out work, before something else has resupply the ATP. When starting up, the ADP then gets restored to ATP by another system (Creatine Phosphate, or CP) but which only carries enough supply in the muscle for about 10-15 seconds of energy supply to the muscle. It’s called the “Anaerobic Alactic” system because it produces muscle contraction without using oxygen (anaerobic) and without making lactates (alactic).

When a person starts any physical activity cold, the first 10-15 seconds is done on this “anaerobic alactic” energy system – the muscles contract through the conversion of ATP into ADP+P+energy, and the ADP is restored to ATP with a P from CP until the supply of CP essentially runs out. During the time the Alactic system is supplying energy, the “Anaerobic Lactic” (works without oxygen, and does produce lactate) system is starting to supply energy so that the person can continue working at almost the same pace as with the Anaerobic Alactic phase of the session.

One difficulty is that no matter what you’re doing, at whatever effort level, at the start of a session, the “aerobic” system of energy production is essentially asleep. When it’s “warmed up” it produces about 80% of the energy needed for racing, but when it’s cold, it produces nearly nothing – so ALMOST ALL of the energy for the first three to five minutes of ANY activity is “anaerobic” – and causes lactate production.

After about three to five minutes of activity, the aerobic system “realises” (yes, it’s an energy system and shouldn’t be anthropomorphised) it’s going to be needed and starts producing energy, AND, if the work rate is low enough, it starts to use as an energy supply some of the lactate that was produced during the early “anaerobic lactic” part of the exercise – (essentially turning the lactate back to pyruvate, and running it through the TCA cycle and the electron transport system) – for non-physiology people, suffice to say that the lactates get burned off.

So – after about 10 minutes of activity, your aerobic system is “up and running” and will have burned off most of the lactates produced in the first few minutes of the exercise session (warm-up).

Then, you can do some short sprints of about 10 strokes that activate your nervous system, and not worry too much about accumulating lactates because your body will be using them up again when you bring the pace back down, AND you won’t be going for long enough to cause lactate to start to accumulate and diffuse from the muscle into the blood stream.

Warming up

A warm up should last long enough to get someone starting to sweat on a relatively cool day. If you time your warm up just right, you get to sit still for about 2-3 minutes before you start your race. And – it’s a good idea to sit dead still for about 2-3 minutes before the race – oops – ergometer test. It’s NOT a good idea to sit still for more than about 5 minutes because your body starts to shut down energy systems that it “thinks” aren’t being used any more.

Why all this palaver about lactates and sitting still?

Imagine starting a race without the aerobic system “warmed up.” Because nothing is “warmed up,” your body produces that initial surge of lactate mentioned above, but because you’re racing, your body doesn’t have a chance to clear it off after the aerobic system gets going – because the aerobic system is not producing enough energy even at it’s maximum rate to satisfy the energy needs of the race. To keep up with the energy required for race-pace rowing your anaerobic system has to fill up the shortfall. So – not only are you working REALLY HARD, but you’re making heaps of lactate in your muscle fibres. When your aerobic system finally does get warmed up, your muscles are already choking in “lactates” and you’re accumulating more with every stroke you take. About 3 minutes into the race… er… ergometer test… you feel as if someone has dropped a very large piano on your head – or you wish someone would do that to put you out of your misery. Lactates, over a certain concentration, interfere with muscle contraction, and interfere with the production of more energy – I think it’s one of those evolutionary protective mechanisms that keep you from turning your muscles into an acid pool that eats itself up. “Ergo” – you need to warm up properly for an ergo-test.

The reason for wanting to sit still for 2-3 minutes before starting a test is the Anaerobic Alactic recovery time – when you stop (STOP) moving, your body somehow knows to replenish the energy supply of the ATP-CP system in a big hurry – so you get very nearly complete recovery of the ATP-CP system in 2-3 minutes of REST (this time it’s not Active Rest).

Here’s a suggestion to make your warm up and your race most effective.

  • Practice good “pre race” nutrition – A regular meal is OK if it’s about 3-4 hours before you start, with the size and greasiness of the meal being reduced, the closer you get to start time. Try to eat very little if anything in the last hour before you race – you want your stomach to be empty before racing, partly so that the stomach doesn’t take any excess blood flow away from your (soon to be) working muscles – and – you don’t want anything in your stomach to come back up to meet you during or shortly after your ergometer test .
  • Jog for about 5 minutes. Spend about 5 minutes loosening and doing a little stretching to ensure you have full range of motion.
  • Get on an ergometer – set the drag factor to that which you test at – in NZ it’s 130 for men, 110 for women.
  • Row 5 minutes at YOUR U2 pace.
  • Row 5 minutes at YOUR U1 pace.
  • Stop for a moment, adjust clothing. Row lightly to keep the aerobic system going, and practice two starts, with light rowing between them.
  • Somewhere, (with or without a start) do a couple of 10-15 stroke “bursts”, but make sure you have at least 10 minutes remaining before your race starts, after the last burst.
  • Row lightly for 5 minutes after the last 10-15 stroke burst.
  • With 5 minutes before your start, row lightly for a minute, and then stop – if you need to secure a heart rate chest strap, do it now. If you feel thirsty, dampen your mouth with some water – if you drink water from mid-warm up on, that water will most likely still be in your stomach when you finish your race. (If you’re thirsty during your warm up, you’re dehydrated, and should have been looking after that before warming up.

Anything you drink in the 10-15 minutes before you test will most likely not be through your stomach and absorbed into your blood stream before you start, unless you’re consuming a properly formulated sports drink, AND your body is prepared for quickly absorbing fluids, AND you don’t have a “nervous” stomach. A “nervous” stomach essentially shuts down fluid absorption, and lets you see what you’ve eaten or drunk, later.) Learn to recognise the difference between being thirsty and wanting to moisten your mouth and throat because you’re nervous. Drink to prevent getting thirsty, and plan your fluids to avoid being thirsty at race time.

  • Report to the testing machine. Position your foot stretcher where you like it. Do NOT offer to change the vent setting – it is most likely that whoever is monitoring the test will have already checked that the drag factor is at the planned setting. You can ask to check the drag factor, but don’t even think about moving the vent until you’ve seen if the DF is off. If you are wearing a heart rate chest strap, make sure it is registering properly on whatever device will be recording.
  • It may or may not be a good idea to do a few strokes before you test – remember that you want to let your Anaerobic Alactic system recover so that you can start strongly, just like in a race.

That’s the warm-up and pre-race preparation.

Doing the test

  • START. A usual racing start – a few strokes, shorter than full length, just like in a boat.
  • REMEMBER TO BREATHE!!!! Most coaches have seen athletes take their first 10 strokes while holding their breath. Not a good idea. What used to work for me was to make sure I blew fully out on the first stroke, forcing me to inhale and keep breathing. Racing or testing, this may help you later in the work piece.
  • Take a few short, very hard strokes, to get the flywheel started.
  • Take MAYBE five (5) hard sprint type strokes – these will be using your Anaerobic Alactic “ATP/CP” energy system, and should not cause you problems later in the piece.
  • Immediately after these (maybe) five strokes, take the pace to your “body of the test” pace, and be very disciplined about staying there. You will have adrenaline and “fresh feeling” going for you early in the piece, but unless you have lots of erg test experience and years of training, it’s easy to overdo the first 500 m.
  • Treat the test like a race – physiologically speaking, a well trained rower will be fastest in the first 500 because they have less metabolic waste interfering with their performance than later on.
  • As the test progresses, you need to keep your stroke length, but your body starts to get tired, you can’t push as hard later on as you could in the first 500. So, if you want to keep from fading, you need to increase the stroke rate. Some coaches suggest one “beat” per 500 m.
  • The second and third 500 (aka the middle thousand) are usually slightly lower in speed because they tend to be run primarily at the “MaxVO2” pace. The closer the Anaerobic Threshold is to the MaxVO2, the faster the person will be able to make it through these two 500 metre segments. The speed profile in international racing (and top level ergometer tests) is dictated by good old muscle and cardiovascular physiology.
  • The last 500 m – well – how far away from the end of the race do you want to start your closing sprint? If you’re brave, you’ll start bumping the rate up gradually from 500 m out. If you’re REALLY brave, you’ll start hammering it from 600 or 700 out and hang on until you can’t see any more. If you’re more conservative, you’ll try bumping the rate from 300 out, and then complain to yourself that you didn’t start to sprint earlier.
  • Keep your length as well as you can, creep the stroke rate up, and see if you have energy to try to break the foot plate in the middle of each drive. Listen to the flywheel and make it zing.
  • At the end – when you’ve finished – try your hardest to stay upright. Most people who crash to the floor and gasp and roll about after they’ve tested are overacting – sure – they’re tired and everything hurts, but a lot more people fall off ergometers than fall out of boats at the end of a really hard 2000m race. If you have the energy to write about showing off how much pain you’re in, you have enough energy to stay sitting (possibly slumped over) and breathe in lots and lots of air. Usually the person monitoring your test will assist you in getting your feet out of the stretchers, and usually there will be someone else around to help you get up on your feet again. If you pass out at the end of a test, the people around you had better be ready to catch you so that you don’t sprain an ankle or knee falling across the ergometer rail with your toe strapped in, but if you’re conscious, and can stay up, it’s a lot safer get your feet out properly.

After the test

After your test – coaches, selectors, and “testers” all know that you’re tired, hurting, and will have trouble moving, but the worst thing you can do for yourself, particularly if you have racing the next day, is sit still. As SOON AS YOU CAN MOVE again, start moving… We know very well that you don’t want to move, but you’ll be able to eventually, and you NEED to move. The best thing you can do for yourself is row an ergometer for another 15-20 minutes.
Lightly – of course – at “U3” or “Active Recovery” pace – or somewhere between 40 and 60% of race speed. Yes.
That’s slow.

What happens to the metabolic wastes that you produce during a race? They are cleared from your body by a variety of mechanisms. The heart muscle can use lactate as a source of energy, so it tends to take a small amount of the lactate out of the blood. The heart itself doesn’t use much blood (it has its own circulation, from the “coronary arteries,” that fill up thanks to back pressure from the other arteries after the heart’s valves have shut after the stroke. The liver clears out some of the lactate by turning it back into something useful, but again, this is a slow process. If you just sit still after a race, and do no “AR” work, you MIGHT return to normal blood lactate levels in TWO DAYS. Not an ideal situation if you have to race the next day. Of course, it’s not really the lactate that’s the problem; it’s the fact that your muscles have become acidified by the production of the lactate that is a big part of the problem.

Rowing lightly for about 20 minutes uses up most of the lactates. When you’re working REALLY HARD, your muscles need more energy than the aerobic system can provide, and the chemical system that makes the extra energy (anaerobic glycolysis, or the anaerobic lactic system) gets “clogged” at the end of its reaction chain by the end product of the chain “Pyruvate”. So – to unclog itself, the body takes this pyruvate molecule and breaks a hydrogen molecule off it to make it into “Lactate” (plus a Hydrogen ion – which is what makes things get “acid”). The Lactate and Hydrogen float around in the muscle and diffuse into the blood stream (this isn’t exactly what happens, but that’s way beyond the need-to-know for this article). Then researchers stick you with a lancet (usually at the earlobe in RowingNZ) and test your lactate levels, but that’s another story. If you keep active, the muscles need energy. A very convenient way to make this energy available quickly is to take the lactate and hydrogen that you made while you were working very hard, smunch them back together to make Pyruvate, shove it through the TCA system and the Electron Transport System, and get a whole heap of ATP for your muscle to use while you do your “row down.”

Essentially, using the muscles that produced the lactates will clear off the lactates much faster than will running or something, because the lactates are mostly in the muscles that produced them – you use the muscles, and you burn off the lactates.

To shorten the story, erging for 15-20 minutes, lightly, will make you feel about 10000% better in a much shorter time, than will sitting on your “duff” and waiting until you feel better. Counterintuitive, perhaps, but true.

Technique during an ergometer test

Effective rowing technique is effective rowing technique – if you row “well,” and have the physical conditioning, it will show up in a good ergometer score and in good times on the water. If you are very strong, and don’t row so well, you may be able to get a good ergometer score but on water speed may suffer. If you are very good in rowing technique but not so strong, you may not get the good ergometer scores, and you won’t catch the people who row well AND have good ergometer scores.

Some people learn to row ergometers differently from how they row a boat. In some circles, this is believed to provide a better ergometer score. In other circles, people change the technique on an erg (pulling to their neck, for example) for the purpose of developing just a little more strength in the hope that it will transfer to the boat.

Unfortunately, when doing a NZ selection ergometer test, this may not be to your benefit, because selectors watch you pull your test, and spend some time being judgmental about a person’s rowing potential because of what you do on the ergometer. Having a pull that’s too low, or over your head, or looking too unconventional will probably not help, unless you manage to “beast” the test, and pull a 5:40 for men, or a 6:40 for women.

Row as much like a boat as you can, and try to leave nothing behind – your 20 minute recovery will help you get ready for the next day’s training, trialling, or whatever comes up. Of course – if you have more time to spend doing recovery work, keep going for up to an hour, but at a low pace.

For a print copy: The 2000m Ergometer Test


Tuesday
Dec062011

Exercise Science and Coaching: Correcting Common Misunderstandings About Endurance Exercise

By: Andrew N. Bosch, PhD
UCT/ MRC Research Unit for Exercise Science and Sports Medicine.
Department of Human Biology, University of Cape Town and Sports Science Institute of South Africa
From: International Journal of Sports Science & Coaching Volume 1 • Number 1 • 2006


Many coaches who work with endurance athletes still believe in old concepts that can no longer be considered correct. Prime amongst these are the understanding, or misunderstanding, of the concepts of maximal oxygen uptake (VO2 max), lactate threshold, training heart rate, and dehydration and fluid requirements during prolonged exercise.

Knowing the VO2 max of an athlete is not particularly useful to the coach, and the exact VO2 max value of any particular athlete can vary considerably as fitness changes. Race performance is a more useful measure on which to base training schedules.

Lactic acid production, far from being an undesirable event, is of great importance and is actually beneficial to the athlete. The lactate concentration during exercise, and the lactate turnpoint, are both widely measured. The nature of the information that these measures can provide about training and training status, however, is still based on information from the 1980s, although more current information is available and many of the original concepts have been modified.

Heart rate is often used to prescribe training intensity, but it is important to understand the limitations inherent in its use. If used correctly, it is a useful tool for the coach.
Similarly, many athletes and coaches still believe that it is necessary to maintain a high fluid intake to avoid dehydration and prevent associated collapse. These beliefs are incorrect, but modern exercise science has been able to advance the knowledge in this area and provide more accurate information.
Exercise science continues to progress and can offer much to the coach willing to accept new and changing ideas.

Key words: Anaerobic threshold; Endurance training; hydration; lactic acid; maximal oxygen uptake; training heart rate

Introduction

Sports science knowledge has progressed tremendously in the last 20 years in terms of the understanding of many of the underlying concepts in exercise physiology and human performance. Many coaches, however, have failed to take cognisance of the new information and still believe in old and out-dated concepts, many of which frankly are wrong. And it is this incorrect understanding that is then applied to the coaching of athletes. In the following article, some of these misconceptions related to endurance performance are highlighted, specifically those around maximal oxygen uptake (VO2 max), lactate threshold, training heart rate, dehydration, and fluid requirements during prolonged exercise. Although runners are most often referred to in the discussion that follows, the principles are applicable to all genre of endurance athlete.

VO2 Max

Every so often a request is received from the coach of a runner or cyclist wanting to know ifit would be possible to measure the VO2 max of one of their athletes. I explain that it is, indeed, possible, but then go on to ask why they want to have the VO2 max of the athlete measured? There is usually one of two replies. Firstly, I am told, by knowing his or her VO2 max the runner will know the esoteric time that he or she is ultimately capable of running for some particular race distance, and therefore their ultimate potential as a runner. Secondly, once their VO2 max is known it will be possible to prescribe the ultimate personalised training schedule. Unfortunately, knowing the VO2 max of a runner does not answer either question.

It is widely believed by those involved in endurance sports that the VO2 max is genetically determined and never changes, and that an individual is born with either a high or low VO2 max. Generally, someone with a high VO2 max value is considered to have a cardiovascular system capable of delivering large amounts of oxygen to the working muscle and is able to exercise at a maximum aerobic work output that is determined by the exercise intensity that can be sustained by this supply of oxygen [1]. In this paradigm it does not appear to matter whether a runner or cyclist is unfit or superbly fit, the VO2 max value obtained in a test is theoretically the same. However, it is intuitively obvious that when fit, the athlete can run much faster on the treadmill than when unfit. Thus, since VO2 max is genetically determined and does not change, VO2 max would be reached at a relatively slow running speed when a runner is unfit compared to when very fit, when a much higher speed or workload can be reached. This means that in a totally unfit world class runner we would measure a high VO2 max (for example, 75 ml/kg/min or higher, a reasonable VO2 max value for an elite runner) at a speed of maybe 17 km/hr in a testing protocol in which the treadmill remains flat during the test. When very fit the same athlete will reach the same VO2 max, but now the speed reached on the treadmill will be around 24 km/hr (a reasonable speed for an elite athlete in such a test). The problem is that such a high VO2 max is never measured at a speed of just 17 km/hr, or thereabout. This would be almost impossibly inefficient [2]. The theory of a genetically set and unchanging VO2 max, regardless of work output therefore begins to appear a little shaky.

This concept of VO2 max evolved originally from misinterpretation of the data of early experimental work [1; 3-5]. It was believed that as an athlete ran faster and faster during a treadmill test, an increasing volume of oxygen was needed by the muscles, a process which continued until the supply of oxygen became limiting, or the ability of the muscle to utilise oxygen was exceeded. At this point there would be no further increase in oxygen uptake, despite further increases in running speed [1]. The plateau in oxygen utilisation was regarded as the VO2 max of the runner. If high, then the athlete had great genetic potential. This has been termed the cardiovascular/ anaerobic model by Noakes [1] and needs revision, although others adhere to the concept [6]. However, 30% of all runners and cyclists tested in exercise laboratories never show a plateau in their oxygen uptake [4; 7]. Instead, the oxygen uptake is still increasing when the athlete cannot continue the test. The conventional view of VO2 max now appears to be even more suspect.

Consider a different possibility. The muscles of a runner require a certain amount of oxygen to sustain contraction at a given speed. When the speed is increased, the muscles have to work harder and there is therefore a corresponding increase in the volume of oxygen needed to run at the higher speed. As the runner runs faster and faster, it follows that there is a concomitant increase in the oxygen required, until ultimately something other than oxygen supply to the muscle prevents the muscle from being able to work harder and to sustain a further increase in running speed.

The brain may be the ultimate subconscious controller, by sensing a pending limitation in the maximum capacity of the coronary blood flow to supply oxygen to the heart as exercise intensity increases, and then preventing a further increase in muscle contractility to prevent damage to the heart during maximal exercise [1].

The volume of oxygen being used by the muscle when maximum running speed has been reached is termed the VO2 max. With this theory, the increase in oxygen requirement merely tracks the increase in running speed, until a peak running speed and therefore peak oxygen requirement (VO2 max) is attained. It is easy to see why the VO2 max value will change (which it does) as a runner gets fitter and becomes capable of running faster. Within this framework, the genetically determined limit of VO2 max is actually determined by the highest running speed that the contractility of the muscles can sustain [8] before the brain limits performance to protect the heart, as described above [1]. Of practical importance, is that the exercise scientist and coach cannot use the VO2 max test as a predictor of future performance in someone who still has the capacity to improve their running by utilising a scientifically designed training programme. A great training-induced increase in running speed will result in a substantial change in VO2 max. Only when widely disparate groups of athletes are tested can a VO2 max value be used to distinguish between athletes (i.e. very fast and very slow [2; 9; 10]). In a group of athletes with similar ability, the VO2 max value cannot distinguish between the faster and slower runners i.e. their race performance. Neither is the knowledge of a VO2 max value going to assist in the construction of a training programme, other than by indirectly giving an indication of the time in which a race may currently be completed, by the use of various tables that are available [11]. Indeed, current race performance provides the most useful information for the coach on which to base training prescription [11].

There are, however, some potential uses of a VO2 max test for a coach. When constructing a training programme for someone who has not run any races and who therefore has no race times from which to determine current ability, a VO2 max test will help by giving an indication of the current capability of the athlete on which to base training schedules. If done at regular intervals, the test can provide information about the efficacy of a training programme [11] as laboratory conditions are very reproducible with regard to temperature and absence of wind. However, the peak speed attained in the test is probably the best indicator of current ability [1; 12-14] and not the actual VO2 max value. Race times remain the most useful measure on which to prescribe running speed in training schedules [11].

Lactic Acid

Most athletes and coaches still believe that lactic acid is released during hard or unaccustomed exercise and that this is what limits performance, as well as being the cause of stiffness. Neither is correct. Furthermore, the terminology “lactic acid,” is not correct.

Lactic acid does not exist as such in the body - it exists as lactate at physiological pH [15], and it is this that is actually measured in the blood when “lactic acid” concentration is measured, as is done when a “lactate threshold” is determined in an athlete. This distinction is important not only for the sake of correctness, but more importantly, because lactate and lactic acid would have different physiological effects.

The first misconception is that lactic acid is the cause of the stiffness felt after an event such as a marathon. Stiffness is due to damage to the muscle [1], and not an accumulation of lactic acid crystals in the muscle [1; 16], as is commonly believed.

The second misconception is that lactate is responsible for acidifying the blood, thereby causing fatigue. To the contrary, the production of lactate is actually important for two reasons. Firstly, when lactate is produced from pyruvate in the muscle, a hydrogen ion is “consumed” in the process [15]. Consequently the production of lactate actually reduces the acidity in the muscle cells and is thus a beneficial process. Secondly, lactate is an important fuel that is used by the muscles during prolonged exercise [17; 18]. It can be produced in one muscle cell and utilized as a fuel in another, or it can be released from the muscle and converted in the liver to glucose, which is then used as an energy source. So rather than cause fatigue, lactate production actually helps to delay fatigue [19].

Anaerobic Threshold

Closely allied to the thinking that lactate production is bad for performance, is the concept of measuring the blood lactate concentration to determine the so-called “anaerobic threshold” or “lactate threshold.”. The origin of this belief can probably be traced to the early studies of Fletcher and Hopkins [20]. Thus we see photographs of athletes at the track or at the side of the pool having a blood sample taken, with an accompanying caption indicating that the workout is being monitored by measuring “lactic acid.” The supposed rationale is that as speed is increased, a point is reached at which there is insufficient oxygen available to the muscle and energy sources that do not require oxygen (oxygen independent pathways, previously termed the anaerobic energy system) then contribute to the energy that is needed. This supposedly results in a disproportionate increase in the blood lactate concentration, a point identified as the “anaerobic” or “oxygen deficient” threshold. This is also known as the lactate threshold or lactate turnpoint.

There are two problems with this concept. First of all, the muscle never becomes anaerobic; there are other reasons for the increase that is measured in blood lactate concentration [21]. Secondly, the so-called disproportionate increase causing a turnpoint is not correct, in that the increase is actually exponential [22-24]. This is seen when many samples are taken, as in the exercise laboratory, where a blood sample can be drawn every 30 seconds as an athlete runs faster and faster.

Although a graph showing a “breakpoint” in lactate concentration as speed increases cannot be drawn as the breakpoint does not exist, a graph can nevertheless be drawn depicting the curvilinear increase in blood lactate concentration as running speed or exercise intensity increases. This curve changes in shape (shifts to the right) as fitness level changes. Particularly, the fitter a runner gets, the more the curve shifts to the right on the graph, meaning that at any given lactate concentration the running speed or work output is higher than before. A shift in the lactate curve to a higher workload or percentage VO2 max occurs due to a reduced rate of lactate production by the muscles and an increased ability of the body to clear the lactate produced [25; 26]. Often, the running speed at a lactate concentration of 4mmol/l is used as a standard for comparison. It is sometimes suggested that this can be used as a guide for training speed (i.e. a runner could do some runs each week at the speed corresponding to the 4mmol/l lactate concentration, some runs above this speed, and recovery runs at a lower speed). Of course, as fitness changes and the curve shifts, these speeds will change, and so a new curve will have to be determined. In concept this works well, but the problem is that neither exercise scientists nor coaches know how much running should be done below, at, and above the 4mmol/l concentration. The 4 mmol/l concentration referred to is a somewhat arbitrarily chosen concentration. It could just as well have been 3.5 mmol/l or 4.5 mmol/l, which would result in different training speeds for the athlete utilizing this system. Indeed, Borch et al [27] suggest 3 mmol/l as the lactate concentration representing an average steady state value. Measuring the maximal steady state lactate concentration may be useful, but requires 4-5 laboratory visits. Thus the real value in determining a ‘lactate curve’ is to monitor how it shifts with training. The desirable shift is one in which a faster running speed is achieved at the same lactate concentration. This regular testing can be done in the laboratory, with the athlete running on a treadmill or on a track, in which running speed can be carefully controlled, such as by means of pace lights.

Training Heart Rate

In recent years the concept of using heart rate while training as an indicator of the correct training intensity, has gained in popularity. Specifically, various heart rate “training zones” have been suggested, and ways to calculate these proposed. This approach has been described in many articles written for coaches and runners [27-29] and does have potential for being a precise way to regulate running intensity in training, particularly for novice runners. However, at present there are no scientific data to support an ideal specific heart rate for different types of training, and much of what is written is based on anecdotal experiences. There is no doubt that future studies will refine this area, making the prescription of training heart rate a more exact science.

Probably the greatest value in heart rate in training is for the coach to use it as a way of ensuring that an athlete does not train too hard on those days when nothing more than an easy training session is prescribed. The use of heart rate for more absolute prescription has the risk of the athlete training at the wrong intensity as a result of the large daily variability in heart rate due to influence of diurnal variation, temperature differences, sleep patterns, and stress [30]. All these can result in the prescribed training heart rate being either too high or too low on a given day. Thus the athlete may train too easily on one day, but on another day when more recovery is needed from a prior hard training session, the training intensity may be too high. The coach is probably better able to assess the most suitable intensity for the athlete. Nevertheless, training intensity based on heart rate may have some value [28].

The use of heart rate as a monitoring tool during training, as opposed to being used to dictate training intensity is a useful aid that coaches can use to assess the training response of an athlete. A progressive decline (over weeks) in heart rate for a given training session would indicate appropriate adaptive response by the athlete; a progressive increase in normal training heart rate would indicate a failure in the adaptive process and that the training load should be adjusted. Similarly, an abnormally high heart rate for a given training session may indicate approaching illness or failure to adapt to the training load and impending overtraining. The athlete would then be well-advised to train only lightly, or to rest [30].

Post-Run Stiffness

In the section on lactic acid, it was stated that the stiffness and muscle pain felt after a marathon or hard workout is not caused by lactic acid. While this was believed to be the case some decades ago, it is now known that lactic acid is not the cause of muscle stiffness, but is the result of damage to the muscle cells, connective tissue and contractile proteins [31-33].

Although the precise cause of delayed onset muscle soreness remains unknown, all runners and coaches are aware that the degree of pain depends on the intensity, duration and type of workout. For example, there is more muscle pain after a long or hard downhill run than after running over flat terrain (i.e. if eccentric muscle actions are emphasised [34]). In fact, it is this phenomenon that begins to exclude a build-up of lactic acid as a cause of the pain. In downhill running, the concentration of lactate in the blood and muscle will be low compared to running at the same speed on the flat. Thus, the most painful post-race stiffness can occur when the lactate concentration is lowest.

If a blood sample is taken from a runner the day after a marathon, especially an ultra- marathon, the concentration of an enzyme, creatine kinase, will be high [35-37]. This is an indication that muscle damage has occurred, as this particular enzyme “leaks” from damaged muscle. The “damage” referred to is minute tears or ruptures of the muscle fibres [38; 39]. This trauma to the muscle can be visualised if a sample of the muscle is examined microscopically. However, it is not just the muscle that is damaged. By measuring the amino acid hydroxyproline, it is possible to show that the connective tissue in and around the muscles is also disrupted [40]. What this shows is that stiffness results from muscle damage and breakdown of connective tissue.

Running fast or running downhill places greater strain on the muscle fibres and connective tissue compared with running on the flat. Downhill running is particularly damaging because of the greater eccentric muscle actions that occur. It is this simultaneous contracting of the muscle while being forced biomechanically to lengthen that is most damaging to muscle fibres.

What does this mean for the runner and coach? From a training and racing point of view, after the muscles have recovered from the damage that caused the stiffness and the adaptive process is complete, the muscle is more resistant to damage from subsequent exercise for up to six weeks [41]. From a coaching point of view, hard training sessions should be withheld when there is muscle pain, as further damage could result. It would be better to allow the appropriate physiological adaptations to take place before resuming hard training sessions. Weight training to increase the strength of the muscle [1] may be beneficial. It has been suggested that vitamin E may help to reduce muscle soreness, but there is little evidence to support this idea [42]. Vitamin E is thought to act as an antioxidant that may blunt the damaging action of free radicals, which attack the cell membrane of the muscle fibre.

It has also been suggested that stretching the painful muscle or muscles may be beneficial, but this has not consistently been shown to alleviate delayed onset muscle soreness. Neither is there any evidence that massage or ultrasound speed up recovery [43]. Similarly, an easy “loosening up” run “to flush out the lactic acid” is unlikely to speed up recovery, although it is also unlikely to result in further damage.

The real cause of muscle stiffness after a hard run is clearly not due to lactic acid in the muscle. Coaches will be in a better position to manage the return to normal training of their athletes after training or racing that has induced muscle soreness, if they understand the effects of type, intensity, and volume of training on muscle stiffness after exercise.

Dehydration, Heat Exhaustion and Heat Stroke

Historically, the understanding has been that runners collapse (most often at the end of races) due to dehydration. This is popularly thought to be more likely when the environmental temperature is high and dehydration more severe. “Heat exhaustion” has been incorrectly thought to be associated with dehydration, yet there is no evidence to support this [1]. “Heat stroke” is an entirely different condition, associated with an increase in body temperature.

There are a number of critical errors in the traditional thinking on the issue of dehydration. Firstly, and possibly most importantly, rectal temperatures are not abnormally elevated in collapsed runners suffering from “dehydration” [44; 45]. Secondly, there is no published evidence that runners with dehydration/ heat exhaustion will develop heat stroke if left untreated [46; 47]. And thirdly, the question must be asked why these runners nearly always collapse at the finish of the race and not during the race. Thus we must look for another explanation as to why the runners collapse.

The explanation is found in a condition called postural hypotension [44; 47-50]. While running, the high heart rate and rhythmic contraction of the leg muscles maintain blood pressure and aids in the return of blood from the legs. When running ceases, the pump action of the leg muscles stops and the heart rate drops rapidly. This results in pooling of the blood in the veins of the lower limb, which in turn causes blood pressure to decrease. It is the lowered blood pressure that results in collapse. Secondly, there is an increase in peripheral blood flow to regulate body temperature. This is more pronounced in hot conditions, and results in a reduction in the pressure of blood filling the heart [51]. Treatment is therefore very simple: If the runner lies down with the legs elevated, the return of blood from the legs is aided, blood pressure is restored and after a short while the runner will have recovered. Cooling the legs may be beneficial. As a preventive measure, it is a good idea to continue to walk after the finish line has been crossed. A second possibility is to lie down as soon as possible and elevate the legs slightly, with cooling of the legs as an additional option.

Heat exhaustion as a result of dehydration does not, therefore, exist and is not a condition that coaches need to be concerned about. This contrasts with heat stroke, in which the body temperature becomes very high (rectal temperature above 41°C) and is a potentially dangerous condition. Even after the athlete has stopped, either voluntarily or because of collapse, the temperature remains elevated because of physiological and biochemical abnormalities in the muscles. Thus the athlete must be cooled as quickly as possible, using methods such as fans, to bring the body temperature down to below 38 degrees Celsius.
Heat stroke develops as a result of a combination of a number of factors. Particularly, a high environmental temperature (>28°C) is more likely to result in the problem than when conditions are cooler. If the humidity is also high, there is an additional heat load on the runner because the sweating mechanism of the body is rendered ineffective. Sweat running off the body, as it does when the humidity is high, does not result in cooling. To cool the surface temperature of the skin, the sweat must evaporate. In addition, and also very importantly, the metabolic heat produced by the runner must be high. Thus, it is the faster athletes who are at risk, who are exercising at a high intensity. It is also, therefore, in races shorter than the marathon in which there is a high likelihood of heat stroke because of the much higher running intensity in shorter races such as cross country (on a hot day) or a 10 km race [46; 47; 52]. Thirdly, it appears that some runners are more susceptible to the development of heat stroke than others [53].

Contrary to popular belief, dehydration is not a major cause of the development of heat stroke. Although adequate fluid replacement during racing in the heat may reduce the risk of heat injury, it is not the only factor and may not even be the most important factor [46; 47; 54; 55]. Arunner can develop heat stroke without being dehydrated. Conversely, a runner can be dehydrated, but not develop heat stroke. If the recommended guidelines for fluid ingestion are followed (~600 ml/ hour), it is very unlikely that fluid deficit will play a role in the development of heat stroke.

Fluid Intake During Exercise

During events such as marathon running, one often reads recommendations suggesting that more than 1L of fluid should be ingested every hour. Ingestion of such a high volume is unnecessary, however, and probably impossible for faster runners to adhere to.

The rate at which fluid ingested during exercise empties from the stomach before being absorbed in the small intestine is influenced by a number of factors. These include the temperature of the fluid, the volume of fluid ingested, and the concentration of any carbohydrate such as glucose, fructose, sucrose or glucose polymer in the water. Thus it is important that athletes follow the correct regimen to ensure optimal fluid and carbohydrate replacement. This consists of ingesting 500-600 ml per hour of a fluid containing 7-10% carbohydrate [56]. This serves two purposes. It supplies a source of carbohydrate to maintain blood glucose concentration, as well as all the fluid replacement that is necessary during prolonged exercise, except possibly under extreme environmental conditions.

Ingestion of too much water during prolonged exercise is not only unnecessary, but can be harmful. In some susceptible people, ingesting large volumes of water can result in a condition called “water intoxication” or hyponatraemia. This occurs when the body’s normal sodium concentration becomes significantly diluted, because the amount of water or sports drink ingested is far in excess of what is needed during exercise to maintain hydration [46; 54; 57; 58]. As with heat stroke, in extreme cases this condition can be life threatening, in this case due to cerebral oedema.

Conclusions

VO2 max testing can be of some limited use to a coach when constructing a training programme for someone who has not run any races. If done regularly, the test can provide information about the efficacy of a training programme. However, the peak speed attained in the test is probably the best indicator of current ability, but race times are the most useful measure on which to prescribe running speed in training schedules.

Rather than cause fatigue, the process of lactate production helps to delay fatigue. In addition, it is important as a fuel substrate. The real value in determining a ‘lactate curve’ is to monitor how it shifts with training, the desirable shift being one in which a faster running speed is achieved at the same lactate concentration.

Heart rate during training is a useful monitoring tool, but should not be used to dictate training intensity. Rather, training heart rate information, together with knowledge of current race speeds and training-induced fatigue, should be used by the coach to determine training intensity. Ultimately, the influence of various parameters that effect heart rate response will be well researched and the coach will then be able to prescribe a specific heart rate for different types of training.

Muscle stiffness after a hard run is not due to lactic acid in the muscle. Return to normal training should be prescribed based on the knowledge that soreness is due to muscle damage.

Dehydration is not a major cause of the development of heat stroke. Heat stroke can occur without dehydration, and conversely, dehydration can occur without heat stroke. If the recommended guidelines for fluid ingestion are followed, it is very unlikely that fluid deficit will play a role in the development of heat stroke.

Ingestion of too much water during prolonged exercise is not only unnecessary, but can be harmful. In some susceptible people, ingesting large volumes of water can result in a condition called “water intoxication” or hyponatraemia.

Despite the exponential increase in knowledge in exercise physiology in the last two decades, the process of exercise physiologists and coaches changing old ideas and concepts and accepting new ones has been slow. Both should examine the new information available and use it to proceed with the next series of research studies and coaching concepts, respectively.

References

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8. Abe, T., Kumagai, K. and Brechue, W.F., Fascicle Length of Leg Muscles is Greater in Sprinters than Distance Runners, Medicine and Science in Sports and Exercise, 2000, 32, 1125-1129.
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10. Pollock, M.L., Submaximal and Maximal Working Capacity of Elite Distance Runners, Part I: Cardiorespiratory Aspects, Annals of the New York Academy of Science, 1977, 301, 310-322.
11. Daniels, J., Daniels’ Running Formula, Human Kinetics, Champaign, IL, 1998.
12. Scrimgeour, A.G., Noakes, T.D., Adams, B. and Myburgh, K., The Influence of Weekly Training Distance on Fractional Utilization of Maximum Aerobic Capacity in Marathon and Ultramarathon Runners, European Journal of Applied Physiology and Occupational Physiology, 1986, 55, 202-209.
13. Noakes, T.D., Implications of Exercise Testing for Prediction of Athletic Performance: A Contemporary Perspective, Medicine and Science in Sports and Exercise, 1988, 20, 319-330.
14. Noakes, T.D, Myburgh, K.H. and Schall, R., Peak Treadmill Running Velocity During the V•O2 Max Test Predicts Running Performance, Journal of Sports Sciences, 1990, 8, 35-45.
15. Robergs, R.A, Ghiasvand, F. and Parker, D., Biochemistry of Exercise-Induced Metabolic Acidosis, American Journal of Physiology – Regulatory, Integrative and Comparative Physiology, 2004, 287, R502- R516.
16. Schwane, J.A., Johnson, S.R., Vandenakker, C.B. and Armstrong, R.B., Delayed-Onset Muscular Soreness and Plasma CPK and LDH Activities After Downhill Running, Medicine and Science in Sports and Exercise, 1983, 15, 51-56.
17. Brooks, G.A., Lactate Production Under Fully Aerobic Conditions: The Lactate Shuttle During Rest and Exercise, Federation Proceedings, 1986, 45, 2924-2929.
18. Brooks, G.A., The Lactate Shuttle During Exercise and Recovery, Medicine and Science in Sports and Exercise, 1986, 18, 360-368.
19. Rauch, H.G., Hawley, J.A., Noakes, T.D. and Dennis, S.C., Fuel Metabolism During Ultra-Endurance Exercise, Pflugers Archives, 1998, 436, 211-219.
20. Fletcher, W.M. and Hopkins, W.G., Lactic Acid in Amphibian Muscle, Journal of Physiology, 1907, 35, 247- 309.
21. Richardson, R.S., Noyszewski, E.A., Leigh, J.S. and Wagner, P.D., Lactate Efflux from Exercising Human Skeletal Muscle: Role of Intracellular PO2, Journal of Applied Physiology, 1998, 85, 627-634.
22. Dennis, S.C., Noakes, T.D. and Bosch, A.N., Ventilation and Blood Lactate Increase Exponentially During Incremental Exercise, Journal of Sports Sciences, 1992, 10, 437-449.
23. Campbell, M.E., Hughson, R.L. and Green, H.J., Continuous Increase in Blood Lactate Concentration During Different Ramp Exercise Protocols, Journal of Applied Physiology, 1989, 66, 1104-1107.
24. Hughson, R.L., Weisiger, K.H. and Swanson, G.D., Blood Lactate Concentration Increases as a Continuous Function in Progressive Exercise, Journal of Applied Physiology, 1987, 62, 1975-1981.
25. MacRae, H.S., Dennis, S.C., Bosch, A.N. and Noakes, T.D., Effects of Training on Lactate Production and Removal During Progressive Exercise in Humans, Journal of Applied Physiology, 1992, 72,1649-1656.
26. Bergman, B.C., Wolfel, E.E., Butterfield, G.E., Lopaschuk, G.D., Casazza G.A., Horning, M.A. and Brooks, G.A., Active Muscle and Whole Body Lactate Kinetics After Endurance Training in Men, Journal of Applied Physiology, 1999, 87, 1684-1696.
27. Pfitzinger, P., Training with Heart Rate, Running Times, 1994, 64-67.
28. Edwards, S., Smart Heart. High Performance Heart Zone Training, Heart Zones Company, Sacremento, California, 1997.
29. Gallagher, J., Using Your Body’s Tachometer, Marathon & Beyond, 1997, 1, 45-56.
30. Lambert, M.I., Mbambo, Z.H. and St Clair Gibson, A., Heart Rate During Training and Competition for Long-Distance Running, Journal of Sports Sciences, 1998, 16, S85-S90.
31. Clarkson, P.M. and Sayers, S.P., Etiology of Exercise-Induced Muscle Damage, Canadian Journal of Applied Physiology, 1999, 24, 234-248.
32. Morgan, D.L. and Allen, D.G., Early Events in Stretch-Induced Muscle Damage, Journal of Applied Physiology, 1999, 87, 2007-2015.
33. Jones, D.A., Newham, D.J. and Clarkson, P.M., Skeletal Muscle Stiffness and Pain Following Eccentric Exercise of the Elbow Flexors, Pain, 1987, 30, 233-242.
34. Clarkson, P.M., Nosaka, K. and Braun, B., Muscle Function After Exercise-Induced Muscle Damage and Rapid Adaptation, Medicine and Science in Sports and Exercise, 1992, 24, 512-520.
35. Noakes, T.D., Challenging Beliefs: Ex Africa Semper Aliquid Novi, Medicine and Science in Sports and Exercise, 1997, 29, 571-590.
36. Noakes, T.D, Kotzenberg, G., McArthur, P.S. and Dykman, J., Elevated Serum Creatine Kinase MB and Creatine Kinase BB-Isoenzyme Fractions After Ultra-Marathon Running, European Journal of Applied Physiology and Occupational Physiology, 1983, 52, 75-79.
37. Strachan, A.F., Noakes, T.D., Kotzenberg, G., Nel, A.E. and de Beer, F.C., C-Reactive Protein Concentrations During Long Distance Running, British Medical Journal: Clinical Research Edition, 1984, 289, 1249-1251.
38. Friden, J., Seger, J., Sjostrom, M. and Ekblom, B., Adaptive Response in Human Skeletal Muscle Subjected to Prolonged Eccentric Training, International Journal of Sports Medicine, 1983, 4, 177-183.
39. Friden, J., Muscle Soreness After Exercise: Implications of Morphological Changes, International Journal of Sports Medicine, 1984, 5, 57-66.
40. Friden, J., Sjostrom, M. and Ekblom, B., Myofibrillar Damage Following Intense Eccentric Exercise in Man, International Journal of Sports Medicine, 1983, 4, 170-176.
41. Byrnes, W.C., Clarkson, P.M., White, J.S., Hsieh,S.S., Frykman, P.N. and Maughan, R.J., Delayed Onset Muscle Soreness Following Repeated Bouts of Downhill Running, Journal of Applied Physiology, 1985, 59, 710-715.
42. Jackson, M.J., Muscle Damage During Exercise: Possible Role of Free Radicals and Protective Effect of Vitamin E. Proceedings of the Nutrition Society, 1987, 46, 77-80.
43. Tiidus, P.M., Massage and Ultrasound as Therapeutic Modalities in Exercise-Induced Muscle Damage, Canadian Journal of Applied Physiology, 1999, 24, 267-278.
44. Holtzhausen, L.M., Noakes, T.D., Kroning, B., de Klerk, M., Roberts, M. and Emsley, R., Clinical and Biochemical Characteristics of Collapsed Ultra-Marathon Runners, Medicine and Science in Sports and Exercise, 1994, 26, 1095-1101.
45. Roberts, W.O., A 12-yr Profile of Medical Injury and Illness for the Twin Cities Marathon, Medicine and Science in Sports and Exercise, 2000, 32, 1549-1555.
46. Noakes, T.D., Fluid Replacement During Exercise, Exercise and Sport Sciences Reviews, 1993, 21, 297-330.
47. Noakes, T.D., Dehydration During Exercise: What are the Real Dangers? Clinical Journal of Sport Medicine, 1995, 5, 123-128.
48. Holtzhausen, L.M. and Noakes, T.D., The Prevalence and Significance of Post-Exercise (Postural) Hypotension in Ultramarathon Runners, Medicine and Science in Sports and Exercise, 1995, 27, 1595-1601.
49. Holtzhausen, L.M. and Noakes, T.D., Collapsed Ultraendurance Athlete: Proposed Mechanisms and an Approach to Management, Clinical Journal of Sport Medicine, 1997, 7, 292-301.
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52. Noakes, T.D., Myburgh, K.H., du Plessis, J., Lang, L., Lambert, M., van der Riet, C. and Schall, R., Metabolic Rate, Not Percent Dehydration, Predicts Rectal Temperature in Marathon Runners, Medicine and Science in Sports and Exercise, 1991, 23, 443-449.
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57. Shephard, R. J. and Kavanagh, T. J., Biochemical Changes with Marathon Running, Observations on Post- Coronary Patients, Proceedings of the 2nd International Symposium on Biochemistry of Exercise, Metabolic Adaptation to Prolonged Physical Exercise, Magglingen, Switzerland, 1973, 245-252.
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Saturday
Nov192011

Mike Spracklen: Australian Rowing Coaching Conference 1995: Video

About Spracklen

Mike Spracklen (born 15 September 1937 in Marlow, Buckinghamshire, England) is an international rowing coach who has led teams from Great Britain, USA, Canada to success at the Olympic games and Rowing World Championships, including the early Olympic successes of Steven Redgrave. In 2002 he was named the International Rowing Federation coach of the year.[1]

  


Career

Spracklen's first major success was in coaching the Great Britain double scull to silver in the Montreal Olympic Games 1976. In 1984 he coached the coxed four to victory at the Los Angeles Olympics It was the first gold since 1948. From that crew he took Steve Redgrave and Andy Holmes to a further Olympic gold in the coxless pair (and bronze in the coxed pair) in Seoul in 1988, before moving to Canada as head coach in 1989 and becoming a full time professional coach.
 
The Canadian men's eight took gold at the 1992 Olympics under his tutelage, and Spracklen moved on to coach the USA squad.[3] He inaugurated the rowing venue at the new Chula Vista Olympic Training Center. After a disappointing finishing position of fifth in the 1996 Atlanta Olympic eights, he returned to Great Britain as the Women's national coach.
 
In 1998 the British women achieved their first Gold at a World Championship, in the double sculls. After the 2000 Olympics, where the British women took silver in the quad,the first Olympic medal for British women, Spracklen's contract was not renewed, with the BBC reporting discontent in the squad over his methods.[4]
 
Since 2000 Spracklen has been coaching the Canadian men's squad, winning the Gold medal for eights at the 2002, 2003 and 2007 World Championships[5] and at the 2008 Olympics.

Australian Rowing Coaching Conference 1995: Part 1

 

 

 

 

 

 

 

 

Australian Rowing Coaching Conference 1995: Part 2

 

 

 

 

 

 

References

1. "Mike Spracklen Named Coach of the Year at FISA's Awards Ceremony". Row2k. 2002-11-17. Retrieved 2008-09-22.
2. "Adrian Spracklen". Mercyhurst College Athletics web site. Retrieved 2008-09-22.
3. "USA Men's results 1980–2000". RowingHistory.net. Retrieved 2008-09-22.
4. Phelps, Richard (2000-10-25). "Spracklen's 'crumbling pyramid'". BBC. Retrieved 2008-09-22.
5. "National Team Coaches". Rowing Canada. Retrieved 2008-09-22.


Thursday
Nov172011

Comparison of rowing on a Concept 2 stationary and dynamic ergometer

By: Aaron Benson, Julianne Abendroth, Deborah King and Thomas Swensen
Department of Exercise and Sport Sciences, Center for Health Sciences, Ithaca College, Ithaca, NY, USA
Journal of Sports Science and Medicine (2011) 10, 267-273

Article link: Jssm.org



Abstract


Biomechanical and physiological responses to rowing 1000 m at a power output equivalent to a 2000 m race were compared in 34 collegiate rowers (17 women, 17 men) rowing on a stationary and dynamic Concept 2 ergometer. Stroke ratio, peak handle force, rate of force development, impulse, and respiratory exchange ratio decreased by 15.7, 14.8, 10.9, 10.2 and 1.9%, respectively, on the dynamic ergometer. In contrast, percent time to peak force and stroke rate increased by 10.5 and 12.6%, respectively, during dynamic ergometry; the changes in stroke rate and impulse were greater for men than women. Last, VO2 was 5.1% higher and efficiency 5.3% lower on the dynamic ergometer for men. Collegiate rowers used higher stoke rates and lower peak stroke forces to achieve a similar power output while rowing at race pace on the dynamic ergometer, which may have increased the cardiopulmonary demand and possibly reduced force production in the primary movers. Differences were more pronounced in males than females; this dichotomy may be more due to dynamic ergometer familiarity than sex.

Key words: Biomechanics, physiological response, stroke rate, efficiency, cadence.

Introduction


Competitive rowing is a year-round sport that typically includes the use of rowing ergometers for indoor training and as a means to assess fitness across time. Traditional ergometers are stationary; the rower moves relative to the resistance unit. To better simulate on-water rowing, manufacturers developed dynamic ergometers, in which part or all of the ergometer moves in response to the motion of the athlete. Subsequent research comparing dynamic and stationary ergometry to on-water sculling at fixed stroke rates is equivocal. Elliot et al. (2001) showed that dynamic ergometry and sculling elicited similar biomechanics, whereas Kleshnev (2005) observed shorter drive lengths and higher handle forces during ergometry than sculling. In contrast, in studies comparing dynamic and stationary ergometry at fixed work rates, lower stroke forces and higher stroke rates were observed during dynamic than stationary ergometry (Bernstein et al. 2002; Colloud et al. 2006). Despite the observed differences in rowing biomechanics across stationary and dynamic ergometers at fixed work rates, the physiological responses were similar (Bernstein et al., 2002; Mahony et al., 1999).

The aforementioned studies comparing stationary and dynamic ergometers or sculling and dynamic ergometry used the RowPerfect dynamic ergometer. Shortly after the appearance of the RowPerfect dynamic ergometer, Concept 2 developed a unique dynamic ergometer. On the RowPerfect dynamic ergometer, both the seat and foot stretcher move on the main rail, whereas Concept 2 placed its stationary ergometer on “Slides” so that the entire unit moves relative to the motion of the rower (Figure 1). The moving mass on the Concept 2 dynamic ergometer (35 kg) is more than twice as large as the moving mass on the RowPerfect dynamic ergometer (17 kg).

Given the design differences between the two models, it is uncertain if the findings from the studies comparing the RowPerfect stationary and dynamic ergometers are applicable to the Concept 2 counterparts. The primary purpose of this study was to compare the biomechanical and physiological responses of collegiate rowers rowing at a fixed power output representing their 2000m race pace on Concept 2 stationary and dynamic ergometers. Secondary purposes were to determine if there were differences between males and females and between novice and varsity rowers.

Figure 1. Diagram of the catch and finish positions on the stationary and dynamic Concept 2 ergometer.

Methods


Subjects

Forty-five Division III collegiate rowers gave their written informed consent, as approved by the Ithaca College Human Subjects Review Board, and completed the study during the last weeks of a spring rowing season. All rowers had used the Concept 2 dynamic ergometer during the fall and spring seasons of the current racing year; though, based on the coaches’ qualitative assessment, the women’s teams used the dynamic ergometer more so than the men and varsity athletes more so than novice athletes.

Eleven of the rowers were excluded from subsequent data analysis for not maintaining a constant power output between the stationary ergometer (SE) and dynamic ergometer (DE) trials. Power output on the DE had to be within 2% of the power output on the SE. Accordingly, 34 rowers were included in the study, 17 women and 17 men split amongst 12 novice and 22 varsity rowers. Salient subject characteristics are presented in Table 1.

Protocol

Subjects completed two 1000 m trials at their 2000 m race pace on a Concept 2 Model C ergometer (Concept 2 Inc., Morrisville, VT). One trial was completed with the Concept 2 as a SE and the other with the Concept 2 as a DE. Using a counterbalanced design to eliminate order effects, 23 of the original subjects completed the DE trial first and 22 subjects completed the SE trial first. Warm-up on a DE, stretching, and rest between trials were allowed as desired.

Race pace was calculated by determining the power output for each subject based on his or her average 500 m split during a 2000 m ergometer trail. Subjects were instructed to maintain power output during their SE and DE trials at their pre-determined 2000 m race pace power output by watching the ergometer power display. Additionally, a researcher monitoring the power output on the display verbally cued the subject to hold power output steady if it started to fluctuate. The drag factor on the ergometer was set at 130 for all tests; drag factor setting affects the rate at which the flywheel decelerates. With higher settings, the flywheel decelerates more quickly, resulting in greater drag or required effort to achieve a particular power output.

Data collection and analysis

A 2200 N tension load cell (model #3190011, Bertec Corporation, Columbus, OH) mounted between the handle and chain of the ergometer was used to collect handle forces at 1000 Hz using DATAPAC 2K2 software (RUN Technologies, Mission Viejo, CA), an AM6100 amplifier (Bertec Corporation, Columbus, OH), and a PCM-PCMDAS16/330 A/D board (Computer Boards, Inc., Middleboro, MA). The load cell was calibrated by the manufacturer to 216.8 N/V and validated with known static weights. Handle forces were collected on 36 of the original 45 subjects due to data collection time constraints and load cell availability. Of these 36 subjects, only 28 maintained a power output on the DE within 2% of their SE power output. Subject characteristics of the 28 load cell subjects (14 men, 14 women; 11 novice, 17 varsity) are in Table 2.

From the raw force data, stroke rate, stroke ratio, impulse, peak force, time to peak force, and rate of force development were calculated for each stroke during the last minute of rowing. The catch of each stroke was identified as the point at which force increased above a 10 N threshold, and the finish was the point at which force dropped below 10 N. The drive phase was defined as the time between catch and finish. The recovery phase was defined from the finish of the drive to the next catch.

Stroke ratio was calculated as recovery time divided by drive time. Impulse was the integral of force from catch to finish. Peak force was the maximum force recorded during each stroke. Time to peak force was the time in seconds from the catch to peak force. Time to peak force was also expressed as a percent of stroke time. Rate of force development was calculated by dividing peak force by time to peak force in s. The average of each variable was calculated across strokes from the last minute of rowing and used for all subsequent analyses. The ergometer measured and stored the average power output and stroke rate for each trial. Since it takes two to four minutes to achieve a physiological steady state while rowing at a constant pace, the physiological data were also measured over the last minute, or at the end of trial, depending on the variable (Hagerman 1984). Expired gases were measured with a ParvoMedics True-Max2400 metabolic cart (Consentius Technologies, Sandy, UT), which was recalibrated for every test. The cart used expired gasses to calculate VO2 and the respiratory exchange ratio (RER) every five seconds; the 12 samples preceding trial termination were averaged to obtain data for the final minute. Rowing efficiency (W⋅L-1⋅min-1) was calculated by dividing the average power by absolute VO2 from the final minute of a trial. Heart rate (HR) was tracked throughout a trial with a Polar F1 heart rate monitor (Polar Electro Inc., Lake Success, NY). The maximum HR observed during the final minute was recorded for data analysis. Immediately after each trial, participants rated total body and lower extremity rating of perceived exertion (RPE) on the modified BORG scale (1-10).

Statistical analysis

Power output was evaluated for the SE and DE trials of each subject. Subjects whose DE power output was not within 2% of their SE trial were excluded from the study and not used in the statistical analysis. Biomechanical and physiological variables were analyzed with a mixed model 2 × 2 × 2 ANOVA (ergometer: stationary v. dynamic × sex: male v. female × experience: novice v. varsity) with repeated measures on ergometer at an α-level of 0.05. Significant interactions were explored using independent or dependent t-tests as appropriate. Sidak-Bonferroni adjustments were made to the alpha level for the multiple pairwise comparisons (Sidak, 1967). As suggested by Neter, et al. (1996), the number of pairwise comparisons depended on the specific interaction resulting in new α-levels of 0.0253 for two pairwise comparisons and 0.0127 for four pairwise comparisons. All analyses were performed with SPSS software (SPSS Inc; Chicago, IL).

Results


There were no differences between novice and varsity athletes for any of the measured variables, and thus all data were combined across experience level. Subsequent analyses used 2 × 2 ANOVAs with repeated measures on ergometer to compare differences across ergometer design and between men and women only. Row times were similar between the SE and DE, 220.9 ± 19.6 s and 220.6 ± 19.6 s, respectively. Accordingly, mean power outputs were also similar between SE (272.2 ± 72.2 W) and DE (272.9 ± 72.2 W). Effect sizes for all comparisons were extremely small ranging from 0.01 to 0.05 (Cohen 1969). Dependent t-tests with a Sidak-Bonferroni adjusted alpha level of 0.0083 for the six multiple comparisons revealed no significant differences (p ranging from 0.025 to 0.508) in power output for the SE and DE for all groupings of subjects. Power output for the men was 58% greater than for the women (p < 0.001). In the load cell subgroup, power output for the men was 48% greater than for the women (p < 0.001). These differences decreased when power output was normalized to body mass, with men producing 31% and 28% more power per kg than the women for all subjects and the load cell subjects respectively (p < 0.001). Power outputs in Watts are presented in Table 3.

Biomechanical variables

The 28 rowers in the load cell analysis group were similar in age, height, mass, and years of experience as compared to the entire 34 rowers as determined with independent t tests (p > 0.278 all variables). Moreover, there was no significant difference between experience level (p = 0.752) between the men and women of this subgroup; though, height and mass were significantly different between the 14 males and 14 females (independent t-tests, p < 0.001 both variables).

There was no difference (p = 0.532) in stroke rate, measured in strokes per minute (spm) between the men, 30.6 ± 3.2 spm, and women, 30.1 ± 2.4 spm. Stroke rate was 12.6% higher on the DE (p < 0.001); the change in stroke rate was greater for the men, 15.5%, than for the women, 9.8%, (p = 0.026). Stroke ratio was 0.34 lower on the DE than the SE (p < 0.001). Impulse and peak handle force were 67 and 36% greater for the men than women, respectively (p < 0.001 both variables). Both impulse and peak force were lower (p < 0.001 both variables) on DE than the SE, decreasing 10.2 and 14.8%, respectively. The drop in impulse, 44.6 N·s for the men and 21.1 N·s for the women, was greater for men than women (p < 0.001). Absolute time to peak force, expressed in seconds, did not change across ergometers (p = 0.609); however, when expressed relative to stroke time, percent time to peak force occurred 1.2% later in the stroke (p < 0.001) on the DE, 15.3 ± 2.2%, than on the SE, 13.8 ± 3.0%. Rate of force development (RFD) was 12% lower on the DE as compared to the SE (p = 0.006). Moreover, RFD was greater (p < 0.001) for the men, 3053 ± 726 N·s-1, than for the women, 2196 ± 511 N·s-1. Table 4 shows the biomechanical data and Figure 2 depicts the average force profiles separated by ergometer and sex.

Physiological variables

Table 5 shows the physiological data. Heart rate was 1.7% lower for males as compared to females (p = 0.008). Absolute and relative VO2 were higher during DE than SE (p ≤ 0.017); this difference resulted from the changes in the men, whose VO2 was 0.24 L·min-1 or 2.80 ml·kg-1· min-1 higher on the DE than SE (p ≤ 0.007). There was no difference in VO2 for the women between ergometers.

The women did have lower absolute and relative VO2 than the men on both machines (p < 0.001). Men were 8.3 W·L-1·min-1 more efficient than women on the SE (p = 0.003). Male efficiency dropped 2.3 W·L-1·min-1 on the DE relative to the SE (p = 0.018). Total body and lower extremity RPE were similar on the DE (7.5 ± 1.4 and 7.1 ± 1.5, respectively) and SE (7.6 ± 1.0 and 7.4 ± 1.2, respectively), and RER was 1.9% lower on the DE than the SE (p = 0.016).

Discussion


The primary purpose of this study was to compare the biomechanical and physiological responses of collegiate rowers at a constant 2000 m race pace power output on a Concept 2 stationary and dynamic ergometer. Stroke rate and percent time to peak force were higher at fixed workloads during dynamic ergometry than during stationary ergometry. In contrast, stroke ratio, impulse, peak force, and RER were lower during dynamic than stationary ergometry. Secondary purposes were to investigate differences between novice and varsity rowers and between male and female rowers. Males had overall higher power outputs accompanied by higher peak handles forces and impulses than the females. The lack of effect of experience, novice v. varsity, observed in this study could be related to the end of the season data collection. One year of on-water and ergometry rowing may have sufficiently minimized differences in the physiological and biomechanical variables measured during SE and DE ergometry in the novice and varsity athlete. Alternatively, it is possible that constraints of ergometry rowing minimize technique and physiological differences between novice and varsity rowers that may be present during on-water rowing.

Biomechanical variables

Stroke rates were similar on the stationary ergometer between males and females and increased an average of 12.6% on the dynamic ergometer when maintaining a fixed power output. The higher stroke rate observed on the Concept 2 dynamic ergometer is similar in magnitude to the increase previously measured on the RowPerfect dynamic ergometer relative to its stationary model (Bernstein et al., 2002). Stroke ratio also decreased 13.5 and 17.8% for women and men respectively during dynamic ergometry due to a drop in recovery time; drive time was similar for all subjects across ergometers (approximately 0.67 s). These results support findings that show increases in stroke rate are accomplished by decreases in recovery time (Dawson et al., 1998; Torres-Moreno et al., 2000). The increase in stroke rate from stationary to dynamic ergometry in the current study was larger for men than women (15.5 vs. 9.8%, respectively). According to the coaches, the female rowers utilized the dynamic ergometers more frequently during practice than the male rowers. The additional training may have enabled the female rowers to apply force more effectively during dynamic ergometry, resulting in fewer strokes per minute to obtain their specified power output as compared to the men. The larger decrease in impulse for men (12.0%) on the dynamic ergometer than women (7.7%) substantiates this supposition. To maintain power output, the men’s larger drop in impulse was counterbalanced by a greater increase in stroke rate on the dynamic ergometer, while the women, who had a smaller drop in impulse on the dynamic ergometer, did not have as large an increase in stroke rate. Due to the purported disparity in dynamic ergometry use by the male and female rowers in this study, the result may reflect additional experience on the dynamic ergometer as opposed to inherent sex differences.

Peak handle forces were also lower on the dynamic ergometer than on its stationary counterpart when rowing at fixed power outputs; these differences are consistent with changes seen on the RowPerfect dynamic ergometer relative to its stationary model (Bernstein et al. 2002; Colloud et al. 2006). Peak handle force data are similar to the handle force data observed during on-water rowing in an eight, which suggests that the Concept 2 dynamic ergometer approximates on-water rowing conditions in such boats (Ishiko et al., 1983; Zatsiorsky and Yakunin, 1991). The dynamic ergometer peak handle force and impulse data of the current study are, however, approximately 20% lower than those reported in a study of brief duration maximum rowing on a Concept 2 DE (Benson and Abendroth-Smith, 2004). The differences in impulse and peak force between the studies are expected given the different work tasks. The subjects in the Benson and Abendroth-Smith (2004) study, also Division III collegiate rowers, generated maximum power output in 20 strokes, whereas the subjects in the current study completed 1000 m pieces at their 2000 m race pace. The subjects in the 2004 study likely used stroke force to increase power output, as opposed to relying on stroke rate alone or a combination of stroke rate and stroke force, to maximize power output. Time to peak force, stroke ratio, and stroke rates were similar between the current study and the Benson and Abendroth-Smith (2004) study.

While absolute time to peak force was similar across ergometers in the current study, percent time to peak force increased from stationary to dynamic ergometer. More importantly, rate of force development was lower on the dynamic ergometer. The lower peak force and lower rate of force development are visually evident from the force-time profiles (Figure 2).

Also apparent on the force curves, though not quantified, is a more drastic change in slope, or RFD, approximately 10% into the stroke cycle on the dynamic ergometer. This apparently steeper slope just following the catch transitioning to a lower RFD before peak force is consistent across rowers and has been observed in other studies for both on-water and dynamic ergometry rowing (Bernstein et al., 2002; Elliot et al., 2001; Martindale and Robertson, 1984).

Kleshnev and Kleshneva (1995) proposed that the absence of the change of slope between the catch and peak force on a stationary ergometer may be due to disparity between foot stretcher and handle force. Alternatively, the subtle differences in RFD between the ergometers could be due to the smaller ergometer mass being accelerated on the dynamic ergometer, which is approximately 35 kg for the Concept 2. On the stationary ergometer, in contrast, the rower accelerates his or her body mass with each stroke, which was 69.0 ± 7.2 kg and 80.0 ± 10.0 kg for the women and men, respectively. The lighter mass may allow forces to be developed more quickly just after the catch and may better approximate the mechanics of on-water rowing, which may be advantageous for offwater training for competitive rowers. Collectively, the biomechanical data reported in this and other rowing studies show that athletes pull more strokes per minute with less force per stroke on a dynamic ergometer compared to its stationary counterpart at a fixed power output (Bernstein et al., 2002; Colloud et al., 2006). The reduced force per stoke observed on the dynamic ergometer may reflect a decreased effectiveness at transferring propulsive force during dynamic ergometry. The force change requires rowers to pull more strokes per minute to maintain the same power output, which they do by decreasing recovery rather than drive time (Dawson et al., 1998; Torres-Moreno et al., 2000). All the aforementioned biomechanical differences allow dynamic ergometry to better simulate actual rowing or sculling (Elliot et al., 2001; Kleshnev, 2005).

Physiological data

The increased VO2 and decreased efficiency on the dynamic ergometer for the men rowing at a fixed power output may be a consequence of the stroke rate change. Similar changes in VO2 and efficiency or economy occur as cadence increases at various power outputs in trained to well-trained male cyclists (Chavarren and Calbret, 1990; Coast and Welch, 1985; Hagberg et al., 1981; Marsh and Martin, 1997; Nielsen et al., 2004; Takaishi et al., 1998). The VO2 changes in the male subjects in the current study, however, contrast with data from an earlier rowing study, which showed that VO2 was similar during incremental tests to exhaustion on a RowPerfect stationary and dynamic ergometer in elite male rowers (Mahony et al., 1999). The inconsistency in VO2 data between the current study and Mahony et al. (1999) may be due to differences in subject fitness and dynamic ergometer familiarity. Indeed, VO2 was similar across conditions for the female subjects in this study, who were more highly ranked than the male subjects, and, who like the subjects in Mahony et al. (1999), were more experienced on the dynamic ergometer. Data from cycling studies support the hypothesis that subject fitness and dynamic ergometer experience affect VO2 as stroke rate increases at a fixed power output. The cycling data show that VO2 increases to a greater extent in less experienced and less fit males at higher cadences across various power outputs than it does in more fit and more experienced males (Marsh and Martin, 1993; 1997; Takaishi et al., 1998). A possible explanation for the 5.0% increase in VO2 in the male rowers in this study during dynamic ergometry is that they had to increase internal muscular work to achieve the specified workload. Perhaps the males’ relative inexperience with the dynamic ergometer required them to increase synergist and core muscle activation to produce the specified power output during dynamic ergometry. Data from cycling studies support this supposition and show that inexperienced males have higher muscle EMG as cadence rises across various power outputs than experienced male cyclists (MacIntosh et al., 2000; Takaishi et al., 1998).

The difference in RER between conditions in the subjects in this study was 1.9% with a small to moderate effect size of 0.3, suggesting a small but possibly meaningful change. RER values above 1.00, as seen in both conditions, indicate increased buffering of plasma lactate, and correspond to elevated levels of anaerobic metabolism in the working musculature (Brooks at al., 2000). The small but significantly lower RER on the dynamic ergometer relative to its stationary counterpart at a fixed power output suggests that anaerobic ATP production was reduced during dynamic ergometry, reflecting a possible decrease in metabolic activity in the primary movers, a supposition supported by the lower impulse and peak handle forces measured during dynamic ergometry.

Lower extremity RPE data are inconsistent with the aforementioned hypothesis. The most probable explanation for the lack of change across ergometers in lower extremity RPE specifically, and whole body RPE generally, is that the subjects based their perceived exertion primarily on intensity, which was similar across trials. Since the subjects trained regularly at that intensity, they probably had well-formed notions of how they should feel after a 1000 m work bout. In short, the sensitivity of the RPE scale may be insufficient to measure potentially small but significant changes as were observed in VO2 and RER.

Collectively, physiological data show that the cardiopulmonary load was greater during dynamic ergometry at a fixed power output in some subjects; the data also suggest that anaerobic metabolic activity in the primary movers was reduced. These changes likely resulted from the higher stroke rates needed to produce the same power output while rowing on the dynamic ergometer. These findings are consistent with the literature on cyclists, which shows that greater exercise cadences reduce primary mover force production and increase aerobic demand (Chavarren and Calbret, 1990; Coast and Welch, 1985; Hagberg et al., 1981; Marsh and Martin, 1997; MacIntosh et al., 2000; Moritani and Muro, 1987; Nesi et al., 2004; Nielsen et al., 2004; Sparrow et al., 1999; Takaishi et al. 1998).

Together, the findings suggest that biomechanical and physiological changes occur in dynamic ergometry compared to stationary ergometry at constant power outputs Decreases in peak handle force and impulse on the dynamic ergometer were accompanied by increases in stroke rate between ergometers. It is possible that some of these differences were a product of the experimental design, which allowed stroke rate to vary across ergometer as the subjects rowed at a constant power output. Consequently, in future studies comparing stationary and dynamic ergometers, scientists may wish to control both power output and stroke rate to determine if there are genuine differences in the biomechanical and physiological response between the two designs. Future studies should also examine stationary and dynamic ergometry under race conditions to determine if either ergometer results in a greater power output over a fixed distance and elicits different biomechanical adaptations and physiological responses. The biomechanical and physiological changes in this study may also have been influenced by experience and training time on the dynamic ergometer, which was not controlled. The larger changes in impulse and stroke rate accompanied by a larger increase in VO2 and drop in efficiency for the males was confounded by the men being not as experienced with dynamic ergometry nor as accomplished rowers as the females. Thus, it is difficult to determine the root cause for the less effective force application and increased cardiopulmonary demand observed in the male subjects on the dynamic ergometer. Future studies should examine stationary and dynamic ergometry following a season of standardized training on the stationary and dynamic ergometers.

Conclusion


Collegiate rowers used higher stoke rates and lower stroke forces to achieve a similar power output on the dynamic Concept 2 ergometer than its stationary counterpart. These changes increased the cardiopulmonary demand in some rowers and possibly reduced force production in the primary movers. The differences were more pronounced in males than females; this dichotomy may be due to dynamic ergometer familiarity more than sex. These results have important implications for athletes training on Concept 2 stationary and dynamic ergometers. Depending on the athlete, stationary and dynamic ergometry may be equally useful for cardiopulmonary fitness, stationary ergometry may best improve force production, and dynamic ergometry may help rowers maintain their feel for the water with more similar force profiles and high stroke rates.

Key points

• When rowing at a constant power output, all rowers used higher stroke rates and lower stroke forces on the Concept 2 Dynamic ergometer as compared to the Concept 2 Stationary ergometer.

• When rowing at a constant power output, cardiopulmonary demand was higher for all rowers, as measured by heart rate, on the Concept 2 Dynamic ergometer as compared to the Concept 2 Stationary ergometer.

• When rowing at a constant power output, efficiency was lower for male rowers on the Concept 2 Dynamic ergometer as compared to the Concept 2 Stationary ergometer.

Acknowledgment


This paper is dedicated to the memory of Julie Abendroth.

References


Benson, A. and Abendroth-Smith, J. (2004) Effects of elbow flexion at the catch position on the force profile of ergonometric rowing. Medicine Science and Sport in Exercise 36(5), S137.

Bernstein, I.A., Webber, O. and Woledge, R. (2002) An ergonomic comparison of rowing machine designs: possible implications for safety. British Journal of Sports Medicine 36(2), 108-112.

Brooks, G.A., Fahey, T.D., White, T.P. and Baldwin, K.M. (2000) Exercise physiology: human bioenergetics and its application. Mayfield Publishing Company, Mountain View, CA.

Chavarren, J. and Calbret, J.A.L. (1990) Cycling efficiency and pedalling frequency in road cyclists. European Journal of Applied Physiology 80, 555-563.

Cohen, J. (1969) Statistical power analysis for the behavioral sciences. Academic Press, New York.

Colloud, F., Bahuaud, P., Doriot, N., Champely, S. and Cheze, L. (2006) Fixed versus floating stretcher mechanism in rowing ergometers: mechanical aspects. Journal of Sport Sciences 24(5), 479-493.

Coast, R. and Welch, H. (1985) Linear increase in optimal pedal rate with increased power output in cycle ergometry. European Journal of Applied Physiolology 53, 339-342.

Dawson, R.G., Lockwood, R.J., Wilson, J.D. and Freeman, G. (1998) The rowing cycle: Sources of variance and invariance in ergometer and on-the-water performance. Journal of Motor Behavior 30, 33-43.

Elliott, B., Lyttle, A. and Birkett, O. (2001) The RowPerfect ergometer: A training aid for on-water single scull rowing. Sport Biomechanics 1(2), 123-134.

Hagberg, J.M., Mullin, M.D., Giese, M.D., and Spitznagel, E. (1981) Effect of pedalling rate on submaximal exercise responses of competitive cyclists. Journal of Applied Physiology 51(2), 447-451.

Hagerman, F.C. (1984) Applied physiology of rowing. Sports Medicine 1(4), 303-326.

Ishiko, T., Katamoto, S. and Maeshima, T. (1983) Analysis of rowing movements with radiotelemetry. In: Proceedings of the Eighth International Congress of Biomechanics, Nagoya, Japan. Eds:

Matsui, H. and Kobayashi, K. VIII-A & B. Champaign, Illinois: Human Kinetics Publishers, 816-821.

Kleshnev, V. (2005) Comparison of on-water rowing with its simulation on Concept 2 and RowPerfect machines. In: Proceedings of XXIII International Symposium on Biomechanics in Sports. Ed: Q. Wang Q. China Institute of Sport Science, 130-133.

Kleshnev, V. and Kleshneva, E. (1995) Biomechanical features of rowing on devices with mobile or stationary workplace. In: Proceedings of XVth Congress of the International Society of Biomechanics, Jyvaskyla, Finland, 2-6 July 1995, 482-483

MacIntosh, B.R., Neptune, R.R. and Horton, J.F. (2000) Cadence, power, and muscle activation in cycle ergometry. Medicine Science and Sport in Exercise 32(7), 1281-1287.

Mahony, N., Donne, B. and O'Brien, M. (1999) A comparison of physiological responses to rowing on friction-loaded and airbraked ergometers. Journal of Sports Sciences 17, 143-149.

Marsh, A.P. and Martin, P.E. (1993) The association between cycling experience and preferred and most economical cadences. Medicine Science and Sport in Exercise 25(11), 1269-1274.

Marsh, A.P. and Martin, P.E. (1997) Effect of cycling experience, aerobic power, and power output on preferred and most economical cadences. Medicine Science and Sport in Exercise 29(9), 1225-1232.

Martindale, W.O. and Robertson, D.G.E. (1984) Mechanical energy in sculling and in rowing an ergometer. Canadian Journal of Applied Sports Science 9(3), 153-163.

Moritani, T. and Muro, M. (1987) Motor unit activity and surface electromyogram power spectrum during increasing force of contraction. European Journal of Applied Physiology and Occupational Physiology 56(3), 260-265.

Neilsen, J.S., Hansen, E.A. and Sjogaard, G. (2004) Pedalling rate affects endurance performance during high intensity cycling. European Journal of Applied Physiology 92(1-2), 114-120.

Nesi, X., Bosquet, L., Berthoin, S., Dekerle, J. and Pelayo, P. (2004) Effect of a 15% increase in preferred pedal rate on time to exhaustion during heavy exercise. Canadian Journal of Applied Physiology 29(2), 146-156.

Neter, J., Kutner, M.H., Nachtsheim, C.J. and Wasserman, W. (1996) Applied linear statistical models.

McGraw-Hill Companies, Inc., Chicago. Šidàk, Z. (1967) Rectangular confidence region for the means of multivariate normal distributions. Journal of the American Statistical Association 62, 626–633.

Sparrow, W.A., Hughes, K.M., Russell, A.P. and Le Rossignol, P.F. (1999) Effects of practice and preferred rate on perceived exertion, metabolic variables and movement control. Human Movement Science 18(2-3), 137-153.

Takaishi, T., Yamamoto, T., Ono, T., Ito, T. and Moritani, T. (1998) Neuromuscular, metabolic, and kinetic adaptations for skilled pedalling performance in cyclists. Medicine Science and Sport in Exercise 30(3), 442-449.

Torres-Moreno, R., Tanaka, C. and Penny, K.L. (2000) Joint excursion, handle velocity, and applied force: a biomechanical analysis of ergonometric rowing. International Journal of Sports Medicine 21(1), 41-44.

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Thursday
Nov172011

Should boys & girls be coached the same way? 

Craig Stewart, Montana State University, USA

Website link: CoachesInfo


Introduction

"Should I coach girls differently than boys?" That is a question often heard in the private conversations between coaches. Coaching has survived a period in which that question, regardless of its legitimacy, would have instigated ridicule. The mere implication that there might be different methods for coaching the two genders was characterized as an assault on all females.
 
But as the number of athletic opportunities for females increased, the louder the question has become. It is not being asked to identify either gender as less competitive than the other, but by dedicated coaches who sincerely desire to use the best methods to prepare female athletes. 

Purpose of this Study

The purpose of this study was to determine if gender differences existed in former athletes in their perceptions of 'favourite and least favourite' coach characteristics. Former athletes have been identified as valuable sources of information from which little information has been gathered (Anshel, 1990). Smoll and Smith (1996) related athletes' memories and perceptions of coaching behaviours to coaching effectiveness, and stated that the psychological impact of sport participation on athletes could be examined by how players and former players remember their coaches' behaviours. Know and Williams (1999) found that surprisingly little research has been reported on the effects of coaching behaviours and its effectiveness. In their study, they found players who perceived their coaches as being more compatible, evaluated their communication ability and player-support levels of the coach more favourably. Conversely, if athletes disagreed with the coach's goals, personality, and/or beliefs, some psychological needs of the athletes were not met. That failure often resulted in frustration and a loss of self-concept by the player.
 
Therefore, it was hypothesized that if differences existed in how male and female athletes remembered their favourite and least favourite coach, understanding those differences would assist professionals in coach education in the preparation of future coaches. It would assist in clarifying any differences between genders in how each valued specific coaching characteristics, thus contributing to whether one should alter coaching behaviours dependent upon the gender of the athletes. Conversely, if no differences were gleaned in this comparison, that too, would provide valuable insight in coaching methods.
 
Holbrook & Barr, (1997) stated that while coaching females is not significantly different than coaching males, gender differences occur in some psychological domains. They wrote that there are differences in the manner women respond to positive feedback. Also, females seem to value personal improvement over winning more than males, and regard team unity as a stronger motivating factor than males. The authors were adamant, however, that these differences have nothing to do with the female athletes' skill levels, desire and willingness to work, capacity to learn, and mental toughness.
 
The President's Council on Physical Fitness and Sports Report on Physical Activity & Sport in the Lives of Girls (1997) supported Holbrook and Barr that there are more similarities between the genders than differences. However, the report identified specific areas of differences requiring coach awareness. According to the report, females, in general, are more internally motivated by self improvement and goals related to team success and appear more motivated by a cooperative, caring, and sharing team environment. The authors cited Garcia (1994) that some female athletes actually can be 'turned off' by coaches who over emphasize winning. It is not that female athletes want to win any less, but may approach competition differently than male athletes. In some competitive circumstances, female athletes place more emphasis on sportspersonship and 'playing fair', than males. When their team loses, females have a tendency to blame themselves first for the poor performance. Under similar circumstances, males appear to be more 'self' or 'ego' oriented and tend to be more 'win at any cost' in their approach to sport. Males are more apt to break rules to achieve their goals and blame others (the referee, the weather, the coach) when they fail. The causes for the psychologically differences are unknown. They could be gender related, but could also be highly influenced by social or cultural expectations (Gill, 1994).
 
If differences exist, coaches need to be aware of them. That awareness could assist coaches in varying coaching styles to meet the individual needs of the gender being coached. If individualization is achieved, coaches would be assisting both the team, and the individual player, in achieving the highest performance possible. It could also reduce the frustration experienced by coaches who switch between teams of different genders.

Methodology

Students in two, college, coaching classes were asked to complete an in-class assignment. In the assignment, they stated their gender, total number of years they had played organized sport, their main sports, and the highest level they had played. They were then asked to list both the positive qualities of their favourite coach and the negative qualities of their least favourite coach (Stewart, 1993).
 
The descriptive statistics are presented in Tables 1 & 2. The coaching qualities were recorded and categorized following the guidelines of Neuman (1997). The categorization process allowed the author to quantify the final results as the percent of total responses, by gender, in each area.

Table 1: Athletic Experience of Subjects

       

HIGHEST LEVEL OF PLAY

 

N

Athletes

Years Played
(avg)

College
Varsity

College
(other)

High School
Varsity

Other

Females

47

45

10.4

4

2

38

1

Males

84

72

12.1

23

5

40

4

 

Table 2: Sports Played by Subjects

Sport

Females

Males

Basketball

23

10

Football

0

27

Soccer

1

5

Softball/baseball

3

13

Track/cross country

5

7

Volleyball

11

0

Wrestling

0

5

Other

2

5

Total

45

72

 

 

Discussion

The positive category, PERSONALITY, received the most references by both genders (males = 27.8% & females = 19.6%). Within this category were specific behaviours interpreted as being related to a coach's personality (or that which made that coach a unique person)- assertive, cooperative, determined, respected (& respectable), willing to help, dedicated, a quality person, great personality, 'cool' under pressure, responsible, liked coaching, a role model, energetic, and wanted to be there. Likewise, PERSONALITY also was the most frequent reference in the negative responses (males = 32.1% & females = 24.5%). In addition to being the opposite of the positive personality characteristics previously mentioned (unwilling to help, not a role model, not a nice person, not focused, not personable, and a 'jerk' ) other negative behaviours which represented personality were arrogant, disrespectful, indecisive, lazy, too much ego, too relaxed, rude, thought he was God, unreliable, weak willed and irritating.
 
Other positive categories for females which appeared most frequently were COMMUNICATION, POSITIVE and CARED. For males, the next most frequent were CARED, MOTIVATION and KNOWLEDGE. For males, COMMUNICATION (problems), TEACHING SKILLS (lack of), and (playing) FAVORITES were the next most frequent responses in the negative category. For females, NEGATIVE, TEACHING SKILLS, and COMMUNICATION were negative categories mentioned most.
 
Though impossible to verify statistically, perhaps the best representations of similarities and differences between the genders are presented in Tables 3a-4b. Tables 3a and 3b present the frequency of positive responses in percentages of both female and male athletes. In Tables 4a and 4b, the negative responses of the genders are presented.
 
In the positive responses, the greatest numerical differences between the genders occurred on COMMUNICATION, EMOTION, and POSITIVE characteristics of coaches. The females recorded those characteristics more than males. On the other hand, males recorded more responses in positive coaching characteristics in WINNING.
 
The frequency of NEGATIVE coaching characteristics can be found in Tables 4a and 4b with an apparent difference between genders in one area. Only in the category, NEGATIVE, does there appear to be a visible difference between genders with females recording more responses than males.

Conclusions

In the examination of gender differences in sport behaviour, Gill (1994) stated that investigation of these factors is more related to social and psychological characteristics than behaviours directly associated with a specific gender. In addition, she wrote that behaviours and characteristics are neither dichotomous nor biologically based, and the attempt to investigate them is elusive at best. As the society changes in which athletes exist, so do the gender roles of the athletes.
 
The results of this study appear to support that belief. There were more similarities in how males and females remembered and characterized their favourite and least favourite coaches than differences. Both genders valued 'personality' above any characteristic as a positive attribute. While personality is a broad, general descriptor, it certainly provides future coaches with specific behaviours that players remember. Athletes of both genders characterized their favourite coaches as those who were assertive, cooperative, determined, respected (& respectable), willing to help, dedicated, a quality person, great personality, 'cool' under pressure, responsible, liked coaching, a role model, energetic, and wanted to be there. The memories of those athletes can provide future coaches with behavioural guidelines by which to develop their coaching styles.
 
Other positive characteristics which were similar between genders were CARED AND COMMUNICATION. With both genders, these characteristics were remembered by coaching behaviours such as cared for me as a person, cared away from the game, talked to me about school, and asked me about things away from my sport.
 
In contrast, males valued KNOWLEDGE (of the sport) and TEACHING SKILLS more than females. Females appeared to value EMOTION and POSITIVE characteristics of coaches more than males. These findings appear to support the thesis that females tend to be more internalized than males in some motivational aspects of sport. Females are apt to valued performance improvements based upon positive interactions and self-comparisons, while males base some motivational factors on externalized factors which would be impacted by a coach's KNOWLEDGE of the sport and the ability to TEACH. However, females remembered the lack of TEACHING SKILLS as a frequent negative characteristic just as male athletes had.
 
In the comparison of negative memories, the genders were even more similar than with positive attributes of their former coaches. The only obvious differences were in NEGATIVE (more frequently noted by females) and WINNING (more with males). However, those differences were very small. These results seem to accentuate the similarities between the genders.
 
Certainly being remembered as 'favourite' or 'least favourite' coach is not, in itself, an absolute measure of coaching effectiveness. However, since the subjects in this study were experienced athletes with extensive backgrounds in traditional sports, their input should be valued in the determination this area.
 
It has been stated that, in general, most coaches do not understand female athletes as well as they should. That very likely remains true today. Sport clinicians and coach educators should spend more time exploring gender differences among athletes and emphasizing working with young female athletes more. Continued examination will assist coaches, and those who train them, in working with all athletes effectively.
 
Finally, although qualitative data is difficult to analyze statistically, it does provide information that is valuable to provide coaches with knowledge on how players perceived and remembered their behaviours. This study represents but a small contribution to the determination of how best to coach athletes of either gender. Additional work like this is needed to establish other areas of similarities and differences. 

References

Anshel, M. (1990). Sport psychology; From theory to practice. Scottsdale, Az.; Holcomb Hathaway Publishing.
 
Center for Mental Health Services/Substance Abuse and Mental Health Services Administration. (1997). The President's Council on Physical Fitness and Sports Report on Physical Activity & Sport in the Lives of Girls.
 
Garcia, C. (1994). Gender differences in young children's interactions when learning fundamental motor skills. Research Quarterly for Exercise and Sport, 66 (3), 247-255.
 
Gill, D.L. (1992). Gender and sport behavior. In T.S. Horn (Ed.), Advances in sport psychology (pp. 143-160). Champaign, IL; Human Kinetics Publishers.
 
Gill, D.L. (1994). Psychological perspectives on women in sport and exercise. In D.M Costa and S.R. Guthrie (Ed.) Women and sport: Interdisciplinary perpective (pp. 253-284).
 
Holbrook, J. E. & Barr, J. K. (1997). Contemporary coaching: Trends and issues.
 
Carmel, In.; Cooper Publishing Company
 
Kenow, Laura. (1999). Coach-athlete compatibility and athlete's perception of coaching behaviors. Journal of Sport Behavior, 22, (2), 251-259.
 
Neuman, W.L (1997). Social research methods: Qualitative and quantitative approaches. Boston, Ma.; Allyn & Bacon.
 
Smoll, F.L. & Smith, .E. (1996). Children and Youth in Sport: A Biopsychosocial Perspective. Madison, Wi.; Brown & Benchmark Publishing.
 
Stewart, C. (1993). Coaching behaviors: "The way you were, or the way you wished you were". Physical Educator, 50 , 23-30.


Saturday
Nov122011

Coaching the Athlete with Diabetes

Dr. Craig Stewart, Montana State University, MT, USA

Website: CoachesInfo


Introduction

My first encounter with an athlete with diabetes was when coaching an Under 14 competitive soccer team. I thought I had reviewed all the medical releases thoroughly, but soon discovered I had missed a very important detail. After competing in two matches some two hundred miles from home, the team and I stopped for fast food, got in the van and started the four-hour drive home. My goalkeeper was in the passenger seat next to me, and I paid no attention to him as he completed his meal and put on his head-phones. A little later, I was distracted by him taking a small satchel from his 'keeper' bag. He proceeded to pull down his warm-ups and inject himself in the upper thigh with a medical syringe. Fortunately, I have a background in special education and, having taught in public schools, was not distracted to a degree that I drove off the interstate. However, as I visited with him, I was extremely concerned that a player I had known for a significant period had Type 1 diabetes and was required to carefully monitor both his caloric intake and 'blood sugar' levels throughout the day. When necessary, he injected himself with insulin to counter any imbalances that occurred.

Problem

Both the incidence of obesity and diabetes are on the rise in the USA. It has been estimated that obesity in children has increased over 25% in the last decade. While Type 1 diabetes is more associated with children than type 2, the number of athletes who are competing with some type of diabetes should follow the trend of an increase like obesity. When combined with the continued growth in youth participation in sport, it is imperative that all coaches be aware of issues related to care of athletes with diabetes.
 
Diabetes; The condition: Diabetes is a metabolic disorder in which the body either fails to produce insulin (Type 1) or the body is unable to utilize all or some of what is produced (Type 2). Insulin is a hormone that is produced in the pancreas and functions to regulate glucose ('blood sugar') that is ingested into the intestine and absorbed into the blood. Glucose is the primary source of energy in the human organism, and if it is not all used, then it is stored as glycogen in the liver and, to some degree, in the muscles.
 
In Type 1 diabetes, the body is not making insulin at all; therefore, the individual via syringe, or in some cases, an insulin pump, injects it. This type of diabetes usually is diagnosed before age 30 and only affects about 10% of the individuals with diabetes. However, those who have Type 1 usually are at greater risk for some of the serious side effects of the condition.
 
Type 2 diabetes usually occurs later in life (after age 40), is highly related to obesity (about 80% of individuals diagnosed with Type 2 are obese) and is usually controlled by some combination of oral medication and the coordination of calorie intake and exercise.
 
While the two types are different in many respects, the primary symptoms prior to diagnosis are the same. An individual with undiagnosed or untreated diabetes could exhibit frequent urination, excessive thirst, blurred vision, unusual fatigue, weight loss and slow healing of wounds (especially on the extremities). It is extremely important that coaches be aware of these symptoms and refer their concerns to either the parents or the medical staff associated with the team. If undiagnosed, the athlete may suffer severe permanent organ damage.

Medical conditions and potential side effects

An athlete with either type diabetes can compete at the highest levels if proper care is taken. However, even diabetes that is thought to be under control has the potential to cause serious health problems. The primary concern for the athlete who thinks her/his diabetes is being successfully managed is hypoglycemia (low blood sugar). It is possible for an athlete to overdose on insulin or under eat in relationship to the caloric needs. In that case he/she could experience unusual hunger, sweating, loss of concentration, heart palpations, and nausea. Most individuals with an understanding of their condition are well prepared with some type of easily digested carbohydrate (candy, juice, pop, etc) that can counter the early symptoms. With younger athletes or even on away games, the coach has to be prepared with the same type of food that can be given in an emergency.
 
Hyperglycemia (elevated blood sugar) is not only a symptom of both types of diabetes, but can be exacerbated by exercise in some cases. Over time, uncontrolled hyperglycemia can, in addition to aforementioned problems, cause ketoacidosis or an increase in ketones in the blood. In either situation of high levels of glucose or ketones in the blood, the athlete should not participate in exercise or athletic events until both are controlled by medical staff.

Other concerns

Knowledge: Responsible coaches will be as knowledgeable as possible about the overall health of all their athletes. One can never assume that medical records and parent release forms are valid or current. Coaches must go to any length to ensure they know of any health issues of their athletes.

In the case of an athlete with diabetes, coaches must know
a) what type
b) how medicated
c) diet considerations, both in relationship to day to day activities, and in the case of drastic increases in caloric expenditures related to sport participation
d) other side effects
 
One of the effects of diabetes that can have a direct effect on athletic participation is a visional problem including sensitivity to bright sunlight. In the case of my young goalkeeper, by the time he was a varsity athlete his coaches had to present referees with a written medical explanation to referees for him to be allowed to play wearing wrap-around shades.
 
Other possible physical side effects are the need for hydration and the care of any sites on the extremities for infection. Hydration is an important factor for any athlete, but in the athlete with diabetes it is even more important. The strain that the condition places on the body to maintain homeostasis is severe. In an attempt to eliminate excess glucose, athletes with diabetes will urinate more than normal. The fluid lost must be replaced immediately to prevent further damage and a reduction in performance.
 
In addition to the strain on the kidneys and total body hydration, an athlete with diabetes is also at risk for infections. The ability of the body to fight infections is compromised by diabetes. Therefore, coaches must be aware of cuts or scraps suffered by the athlete, as well as, blisters or 'hot spots' on their feet. Even greater care than normal should be given to these seemingly 'minor' medical issues. They should be referred to the team medical staff or discussed with parents as soon as possible. It is highly recommended that athletes have extra clean, dry socks at all practices and matches to assist in foot care.
 
STRESS - the final concern: A coach of an athlete with diabetes should also be aware of the unique relationship between increased levels of stress and hormonal changes in the body. In the normal individual, one of the basic adjustments to stress (even good stress such as increased excitement prior to an important match) is an increase in some hormonal levels which may result in elevated glucose levels. The "fight or flight' syndrome prepares our body to meet the challenge or escapeÉ as quickly as possible. There is no reason to believe that an athlete who has diabetes would react any differently. Unfortunately, the sudden increase in hormones may work again this athlete. Knowledge of this phenomenon by both the coach and the athlete will assist both in meeting the medical challenge as well as the athletic ones.

Conclusion

There have been numerous athletes who have had successful, productive careers and dealt with their diabetic conditions. Coaches need to be aware of the potential of an increase in the number of athletes they might encounter and how to ensure safe and successful athletic careers.
 
Careful coordination and communication between the athlete, his or her family and their physician with the coach and the medical staff of the athletic program is essential. Diabetes is an extremely serious health condition, but with the proper precautions, it should not affect most athletes who suffer from it.

References

Diabetes and Stress. Retrieved January 29, 2003 from http://www.diabetes.org/main/homepage.jsp
 
Diabetic Ketoacidosis, The Merck Manual. Retrieved January 29, 2003 from http://www.merck.com/pubs/mmanual/section2/chapter13/13b.htm
 
Diabetes Mellitus (DM). Retrieved January 29, 2003 from http://www.pharmacy.gov.my/self_care_guide/miscellaneous/ (the Diabetes Mellitus.pdf)
 
Ebeling, P.; Tuominen, J. ; Bourey, R.; Koranyi, L.; & Koivisto, V. (1995) Athletes with IDDM exhibit impaired metabolic control and increased lipid utilization with no increase in insulin sensitivity. (insulin-dependent diabetes mellitus) Diabetes, v44 n4 p471(7)
 
Fahey, P.J.; Stallkamp, E.T & Kwatra, S. (1996). The athlete with type I DIABETES: managing insulin, diet and exercise. American Family Physician. v53 n5 p1611(9)
 
Healthy habits to help manage and prevent type 2 diabetes (Nutrition Fact Sheet) (2002) Journal of American Dietetic Association. Nov. v 102, i11,p1725(2).
 
Hormones of the Pancreas. Retrieved January 29, 2003 from http://www.users.rcn.com/jkimball.ma.ultranet/BiologyPages/P/Pancreas.html
 
Hornsby, W.G. & Albright, A.L. (2003) Diabetes . In Durstine, J.L & Moore, G.E. , editors. Exercise Management for Persons with Chronic Diseases and Disabilities, 2nd edition, (pp.133-141) Champaign, Ill., Human Kinetic Press.
 
Leski, Mark, M.D. Diabetes in the Active Population (book chapter excerpt) Retrieved January 29, 2003 from http://www.med.sc.edu:1082/pdf%20files/Diabetes%20in%20the%20active%20population.pdf
 
Nelson, K.M., Reiber, G. & Boyko, E.J. (2002) Diet and exercise among adults with type 2 diabetes: findings from the Third National Health and Nutrition Examination survey (NHANES III). Diabetes Care. v25, i10, p1722(7).
 
The diabetes prevention program (DPP): description of lifestyle intervention. (2002) Diabetes Care. v25,i12,p2165(7).
 
Safety Tips. Retrieved January 29, 2003 from http://www.diabetes.org/main/health/exercise/safety/25ways.jsp
 
Sherman, M.; Ferrara, C. & Schneider, B. (1996). Nutritional strategies to optimize athletic performance. Clinical Diabetes, v14 n1 p3(6)


Thursday
Nov102011

Rowing Biomechanics

By: Dr Valery Kleshnev (2006):
Rowing Science Consultant
Managing Director, Biorow Ltd

Direct links to Rowing biomecanics news letters, see Biorow and High Performance Rowing Recources.


History

Rowing is one of the oldest human activities and known for more than 5,000 years. Rowing in cane boats by means of long oars can be seen on frescoes from the 5th Dynasty of the Pharaohs in Egypt in 2500 B.C. Rowing races in various types of boats were popular in ancient Greece and Rome. Though rowing was not in the program of ancient Olympic Games, there were evidence that more than 100 boats and 1900 oarsmen participated in rowing regattas organized by Emperors Augustus and Claudius Dal Monte, 1989).

Rowing became popular sport in Europe since the XVII century. The oldest of the currently existing “The boat race” between teams of Ojxford and Cambridge Universities began in 1829. In XIX century races of professional scullers collected multi-thousand crows on banks of the Thames River and millions of pounds were spent on betting, which resembles popularity of modern boxing, tennis and Formula-1 car racing.

International Rowing Federation FISA was founded in 1892. FISA is the oldest international sport federation. Now it includes representatives if 118 National rowing associations.

Rowing is the oldest Olympic sport. Though rowing competition was not held on the first Games in Athens in 1896 due to bad weather conditions, it has always been in the program of the modern Olympic Games. Currently, presence of sports and athletes is limited in Olympic Games. There is very tough competition for a quote. However, rowing managed to maintain the third large quote after athletics and swimming having 14 medals sets and more than 550 athletes participating.

In 2005 adaptive rowing was included in Paralympics, which is also evidence of its growing popularity.

Trends of rowing performance

Long term performance in rowing is difficult to analyse, because it is significantly affected by weather conditions and differences over the courses used during European, World and Olympic events. A more detailed presentation of the progress maybe obtained by comparison of the records from a single regatta and, for that purpose, the Royal Henley Regatta is ideal, because it is the oldest still existing institution in race rowing. It is possible to define the following periods of rowing development, which can be seen on Figure 1:

 

Figure 1. Trend of rowing speed based on records of the Grand Challenge Cup (M8+) of the Royal Henley Regatta

Before 1900 there was a fast growth of performance of 1-1.5% per year, which may be explained by initial development of equipment (timber boats, outriggers, and the sliding seat), in addition to sporting technique and training methods.

The slower growth of ?0.5% per year from 1900 – 1950 may have been caused by the two World Wars, the amateur status of the athletes and the relatively limited competition due to the separation of sport organisations between the East and West political alliances.

However, from 1950 – 1980 performance grew at very fast pace of ?1-2% per year. It can be considered that when Eastern block countries joined Olympic sport in 1952 the competition level was substantially raised. Thus, sport became a political factor and a professional activity, which boomed the training volume, methods and use of drugs in sport. This performance growth was even faster in women, because it coincided with initial development in women’s events.

In the period of 1980 – 1996 there has been a slower growth of ~0.5-0.8% a year. This growth rate could be reflective of the training volume approaching its biological limit; an improvement of the drug control. Rowing performance, however, continues to grow relatively faster than in athletics and swimming. We can speculate that the reasons were equipment development (plastic boats and oar s replaced wooden ones, introduction of the "big blade”) and active FISA position in wider promoting of rowing and popularisation of modern training technologies.

1996 – now. Stable period and even decreasing of performance. We can speculate that the reasons could be further development of doping control methods (such as blood doping test) and sociological factors.

Boat types and rowers’ categories

From its origin up to the 1972 Games rowing had seven male events in Olympic program (1x, 2x, 2-, 2+, 4-, 4+, 8+ on the standard distance 2000 m). In 1976 a number of events was increased to 14: one male event (4x) and six female events (1x, 2x, 4x, 2-, 4-, 8+ on the distance 1000 m) were introduced. Women events changed the distance to the standard 2000m in 1984, which have made female rowing more aerobic with less demand for strength and power. The current Olympic program was introduced after the 1992 Games, when lightweight events were included (LM2x, LM4-, LW2x) on the expense of (M2+, M4+, W4). Yet, these events are included in the World Championships Program. (Table 1)

Boat Type

Men

 

Women

 
 

Heavyweight

Lightweight

Heavyweight

Lightweight

Single scull (1x)

OG

WC

OG

WC

Double scull (2x)

OG

OG

OG

OG

Quad scull (4x)

OG

WC

OG

WC

Pair (2-)

OG

WC

OG

 

Four (4-)

OG

OG

WC

 

Eight (8+)

OG

WC

OG

 

Pair with coxswain (2+)

WC

     

Four with coxswain (4+)

WC

     

 

Table 1. Rowing events in Olympic Games (OG) and World Championships (WC) programs. 

Rigging

Gearing

In sports such as rowing and cycling the term “gearing” is used for a ratio of the velocities of locomotion to the velocity of athlete action. According to the lever law, the ratio of forces is reversely proportional to the ratio of velocities. Athletes, therefore, have to apply proportionally more force as the gearing decrease velocity of their action at constant speed of locomotion. In rowing the gearing is defined by two main variables: oar length versus the inboard length (Figure 2).

Figure 2. Oar gearing variables

The oar length is measured from the handle top to the outer edge of the blade in the line of the shaft. The inboard is measured from the handle top to the face of button. However, actual resultant forces are applied to different points of the blade:

• Point of the handle force application is difficult to locate exactly and it may vary in different rowers. We assume that the handle force is applied at the centre of the handle, which is located 6 cm from the handle top in sculling and 15 cm – in sweep rowing.
• Gate force applied to the centre of the pin, which offsets from the button on the half width of the gate and it is usually 2cm.
• Blade force applied to the centre of water pressure on the blade. It is even more difficult to define and it may vary depending on the angle of attack. We assume it applied at geometrical centre of the blade, which usually located 20 cm from the outer edge in sculling and 25 cm in sweep rowing.

Table 2. Oar gearing (based on Nolte, 2005) and corresponding speed characteristics (based on the World best times for 2006) in different boat types.

Boat Type

Oar Length (m)

Inboard (m)

Actual Inboard (m)

Actual Outboard (m)

Actual Gearing

Boat speed, men (m/s)

Boat speed, women (m/s)

Handle speed, men (m/s)

Handle speed, women (m/s)

1x

2.88

0.88

0.84

1.78

2.119

5.05

4.68

2.38

2.21

2x

2.88

0.88

0.84

1.78

2.119

5.49

5.02

2.59

2.37

4x

2.89

0.875

0.835

1.795

2.150

5.92

5.39

2.76

2.51

2-

3.72

1.16

1.03

2.29

2.223

5.34

4.83

2.40

2.17

4-

3.73

1.15

1.02

2.31

2.265

5.86

 

2.59

 

8+

3.73

1.14

1.01

2.32

2.297

6.25

5.61

2.72

2.44

 

Actual gearing is heavier in sculling than in sweep boats. The variation is small between small and big boats and does not correspond to the difference in the speed of the boat. The difference in the handle speeds between 1x/2- and 4x/8+ is quite significant (12-14%). This leads to the variation of the racing rate, which varies from 34-36str/min in 1x/2- to 39-40 str/min in 4x/8+. Actual gearing is higher (heavier) at the catch and finish of the drive than at the perpendicular position of the oar. At catch and finish the blade moves at the angle to the boat movement and its longitudinal component equal to cosine of the angle. E.g. at the catch angle of 60o the gearing is two times heavier and at 45o it is 30% heavier than at the perpendicular oar position.

Rower’s workplace

It is important to setup the rower’s workplace properly, because its geometry affect vectors of forces and velocities and, hence, efficiency and effectiveness of rowing technique.

  Figure 3. Variables of the rower’s workplace geometry

The main variables are:
• Gate height is measured from seat to the bottom of the oarlock and varies from 14 to 19cm depending on the rower’s height. In sculling the left gate usually 0.5-2 cm higher than the right one.
• Heels depth is measured from seat to the bottom of the shoes and varies from 15 to 22 cm depending on the rower’s body composition.
• Seat height from water varies depending on boat type and weight of the rowers.
• Span in sculling is measured from pin to pin. Spread in sweep rowing is measured from pin to the boat centreline. Usually, the inboard length is longer than the spread in sweep boats or half of the span in sculling boats. This makes overlap measured between tops of the handles in sculling, which is usually 15-20 cm, and between the boat centreline and top of the handle in sweep rowing of 25-30 cm.
• Stretcher position is measured from the pin to the toes of the shoes and is 50-65 cm.
• “Work through” is the distance from the pin to the end of the slides and is 5-12 cm.
• The distance that the seat travels is usually 60-65 cm.
• Stretcher angle varies from 36o to 45o.
• Slides angle is usually set between 0.5o and 1.5o.
• Oar pitch is the angle between vertical line and the blade. In depends on two settings: pitch of the blade relative to the sleeve and the gate pitch. The first one usually set to zero and the second one varies between 2o and 6o. If the pin is leaning inwards, then the pitch at catch will be less and at finish more than it the perpendicular position of the oar. Outwards leaning of the pin produce the opposite changes in the pitch. Usually, the pin is set vertically, but some coaches use 1o-2o outward leaning of the pin, which prevents the blade from going too deep at the catch and too shallow at the finish of the drive.

Mechanics

Propulsion and blade efficiency

When the rower applies force to the oar handle (Fhandle), it is transferred to the blade and applies pressure on the water. According to Newton's 3rd law this creates reaction force on the blade Fr.blade, which is the force that accelerates the rower-boat-oars system (RBOS) forward. During the drive phase, the centre of mass (CM) of the whole system moves forward and the centre of pressure (CP) of the oar slips through the water. Some point on the oar shaft remains stationary and can be considered as an imaginary fulcrum. It is not a real fulcrum because there is no support at this point. The position of the fulcrum changes during the drive phase and depends on the blade propulsive efficiency: the higher the efficiency, the closer fulcrum to the CP of the blade. The fulcrum coincides with CP at 100% efficiency.

Figure 4. Forces in the rower-boat-oar system

Reaction force on the blade is the sum of the drag and the lift forces. As an angle of attack changes through the drive, the ratio of the drag and lift forces changes from 1:2 the angle 60deg at catch to 1:0 at the oar position perpendicular to the boat (Caplan and Gardner, 2005). The lift force does not result in any loss of energy, i.e. it is 100% efficient, because vectors of force and velocity are perpendicular to each other. The vector of the drag force is parallel to the velocity vector and has opposite direction. Waste of energy is calculated as a scalar (dot) product of blade force and velocity vectors. Propulsive power is the product of the force and velocity vectors applied to the CM of RBOS. The sum of the propulsive and the waste posers equals the total power applied to the oar handle. Propulsive efficiency of the blade is a ratio of the propulsive power to the total power. Propulsive efficiency of the blade can be derived by means of measuring instantaneous boat velocity, oar angle and a force at the oar handle or gate (Affeld, 1993, Kleshnev 1999). The force applied to the oar blade (Fb) is calculated using measured handle force and oar gearing. The blade velocity (vb) is derived using oar angle and boat velocity data.

Figure 5. Path of the oar during the stroke cycle

Propulsive efficiency of the blade depends on the relative pressure on the blade, i.e. the ratio of the blade force to the blade area. Lower pressure relates to less slippage of the blade through the water and higher blade propulsive efficiency. To increase efficiency there is a need to reduce blade force or to increase the blade area. The blade force is reduced at the same handle force by means of changing the oar gearing ratio to heavier values (shorter inboard and longer outboard distance). However, very heavy gearing will decrease muscular efficiency of the rower, because the handle speed will decrease and it makes muscles work in slow static-like regimen. Increasing of the blade area is also limited because wider blade takes more time and requires more effort for entry and extraction from the water. A very long blade is also inefficient, because it can create counter-movement effect on opposite sides of the blade. Also, the blade efficiency is affected by the velocity of the boat, and it is higher in faster (bigger) boat types. Sculling has a higher blade efficiency than sweep rowing, which can be explained by higher sum of the blade area. This could be one of the reasons why sculling boat are faster than sweep boats of the same size. The characteristics of the force application affect blade efficiency and may be controlled by the rower. A force curve with a peak increases blade slippage and decreases efficiency. Conversely, a rectangular shape of the force curve affects efficiency positively. There is a moderate correlation between the ratio of average to maximal force, taken as a measure of the shape of the force curve (100% for rectangle, 50% for triangle), and blade efficiency (r = 0.48, p<0.01).

Table 3 Average values of the blade propulsive efficiency based on 1470 crew-samples collected during 1998-2005 in the Australian Institute of Sport (AIS).

 

Men

Woman

Average

Boat Type

Heavy

Light

Heavy

Light

 

1x

79.6%

 

78.5%

 

79.0%

2

78.5%

 

80.6%

 

79.4%

2x

82.3%

81.9%

83.6%

84.1%

83.0%

4-

80.2%

82.1%

80.5%

 

81.0%

4x

83.7%

 

87.3%

 

85.5%

8-

81.4%

 

81.5%

 

81.4%

 

Bigger boats have higher blade efficiency due to higher average speed, which makes lift force more significant. Scullers are efficient because of the bigger total area of the blade. Higher blade efficiency in lightweight women’s crews can be explained by lower force application, which relates to lower relative pressure on the blade and less slippage through the water.

The Vortex Edge blade was introduced in attempt to increase efficiency (Concept 2 web site). The overall improvement of the blade efficiency with Vortex is about 2%. Application of the Vortex shifts the centre of pressure towards the outer edge of the blade, equivalent to increasing the outboard lever of the oar.

Boat Speed: Resistance, Variation, Efficiency

According to fluid dynamics drag resistance force is proportional to the square of boat speed and drag power is proportional to the cube of the velocity. Therefore, if a crew increase the boat speed twice, then they should overcome four times higher drag force and apply eight times more power. Normally, the hydrodynamic resistance of the water represents 85% of the total drag force, which includes 70% water friction, 10% wave resistance and 5% pressure resistance. Aerodynamic resistance normally represents 15%, but at head wind it increases up to 30% at wind speed of 5 m/s and up to 50% of total drag at 10m/s. Correspondingly, in tail wind, air resistance decreases to 0% at wind speed equal to the boat speed. Rowers’ bodies create approximately 75% of air resistance, oars give nearly 20%, and the remaining 5% depend on the boat hull and the riggers. Strait head wind is beneficial for big boats, because the bow rower shields the rest of the crew, which decrease the drag. Cross-head wind has less influence on small boats (Figure 6).

Figure 6. Boat speed at strait (a) and cross (b) winds (Filter, 2000);

Water viscosity decreases at higher water temperature, which decreases hydrodynamic resistance and allows higher boat speeds

Figure 7. Boat speed at different water temperature (Filter, 2000);

Due to the periodic nature of the drive phase in rowing, the boat speed is not constant during the stroke cycle (Figure 8, a). The drag power increases more at a higher than average boat velocity (dash shaded area on Figure 8, a), than it reduces at a lower than average velocity (cross shaded area). The total energy expenditure at variable boat velocity is, therefore, higher compare with constant velocity.

 Figure 8. Deviations ofthe shell velocity and drag power from agerage (a); and Ratio Recovery and Drive (b)

The ratio of the minimal power required to propel the boat at a given constant speed to the actual propulsive power at variable boat velocity is called “Boat efficiency”.
Table 4. Boat Efficiency of rowing in Olympic boat types.

 

Men

Woman

Average

Boat Type

Heavy

Light

Heavy

Light

 

1x

95.1%

 

94.5%

 

94.8%

2-

94.9%

 

95.1%

 

95.0%

2x

94.9%

95.5%

95.4%

96.3%

95.5%

4x

96.2%

 

95.6%

 

95.9%

4-

95.4%

95.3%

91.9%

 

94.2%

8+

96.4%

 

96.5%

 

96.4%

 

For improvement of the boat’s efficiency Sanderson and Martindale suggested optimisation of the rowers’ movement on recovery to maintain the shell speed as constant as possible. In high stroke rates the recovery time is shorter and that dictates faster movement of the rowers’ mass and higher acceleration of the shell. Therefore, the boat velocity fluctuations increase with stroke rate (a), which leads to a decrease of the boat velocity efficiency (b) and stroke rate has a negative correlation with the boat efficiency (r = -0.34, p < 0.05). On average, the boat efficiency drops 1.4% from stroke rate 20 (96.0%) to 40 (94.6%).

Table 5. Boat Efficiency of rowing in Olympic boat types.

 

Men

Woman

Average

Boat Type

Heavy

Light

Heavy

Light

 

1x

95.1%

 

94.5%

 

94.8%

2-

94.9%

 

95.1%

 

95.0%

2x

94.9%

95.5%

95.4%

96.3%

95.5%

4x

96.2%

 

95.6%

 

95.9%

4-

95.4%

95.3%

91.9%

 

94.2%

8+

96.4%

 

96.5%

 

96.4%

 

Newton's Laws of Motion, Kinetic Energy, Centre of Mass

The implication of Newton’s first law is that rowers have to apply force to overcome drag and maintain linear movement of the boat. When force is applied to the blade during the drive phase, an equal and opposite directed reaction force is created, according to the third Newton law. The forward component of this reaction force is the only reason of acceleration of the boat’s centre of mass.

According to Newton’s second law, the magnitude of this acceleration is proportional to the mass of the system and the magnitude of the propulsive force.

When the CM of the boat accelerates, it accumulates kinetic energy, which is spent on overcoming drag resistance and lost as heat to the surroundings of the rowing boat.

However, rowing mechanics is not as simple as it looks. It may appear that the main target of the crew is acceleration of the boat and because the rowers sit in the boat the whole system moves as fast as the boat does. This simplistic observation leads to erroneous coaching theories, which can harm performance in rowing when it is advised to maximise handle-gate force in order to accelerate the boat and at the same time suggesting to minimise the force on the foot stretcher, because it pushes the boat backwards.

The following steps will help to understand the principles of effective rowing technique:
1. To increase the boat speed, rowers have to expend more power to overcome higher drag resistance (P = kv3).
2. The kinetic energy of the whole boat-rower system can be increased (accumulated) only during the drive phase. The increase of the shell's velocity during the recovery is explained by the transfer of the crew’s kinetic energy
3. Because the crew's mass is higher than that of the boat, the crew accumulates 5-6 times more kinetic energy than the boat (Ek = mv2/2). Therefore, the main target for an effective drive phase is to increase the velocity of the crew's centre of mass.
4. The only force accelerating the rower’s centre of mass forward is the reaction force on the stretcher. Therefore, maximizing of the stretcher force is the main target of the drive. The handle force pulls the rower backwards.
5. To apply a high stretcher force is not enough for a rower’s acceleration. The stretcher must have a supporting connection to the water through the rigger and oar.
6. The stretcher (and the whole shell) has to move fast forwards at the moment of the leg drive. Thus, rowing can be considered as a series of jumps where each drive phase is a jump and recovery is a flight phase. With this consideration longer jumps or higher jump frequency results in higher rowing speed. The major difference between rowing and real jumping is that rowers have to create support on the stretcher by placing the blade in the water and applying handle force.

Timing of the stroke cycle

Temporal or phase analysis plays an important role in modern sport biomechanics and is the most versatile biomechanical method of analysis across different sports. Other methods based on mechanical parameters (position, velocity, force, etc.) have very different nature in various sport motions. The phase analysis is based on time only and can represent different motions as a sequence of phases and sub-phases.

The accelerations of the boat, rowers’ and system centre of mass as well as the oar and seat velocity are used for definition of the micro-phases of the stroke cycle. Figure 10 shows biomechanical parameters of a single sculler obtained during detailed measurements.

Six micro-phases of the drive phase (D1-D6) and three micro-phases of the recovery (R1, R2, R3) are defined in Table 6.

Table 6. Micro-phases and key events of the stroke cycle.

No.

Key event description

Micro-phase ID

Micro-phase description

1

Catch, beginning of the drive. Oar changes direction of movement

D1. Blade Immersion

The system’s acceleration is still negative. Small inertial forces applied to the handle and the gate, but the foot-stretcher force is already significant. This produces a negative peak of the boat’s acceleration and a positive peak of the rower's centre of mass acceleration. Fast increase of handle and legs speed

2

The system’s acceleration becomes positive. The centre of the blade crosses the water level

D2. Initial rowers’ acceleration

Handle force increases, which leads to the gain of the boat’s acceleration, but it is still negative and lower than the rowers’ centre of mass acceleration.

3

The boat’s acceleration become higher than the rowers’ centre of mass acceleration. This is caused by the increase of the gate force, which becomes higher than the stretcher force

D3. Initial boat acceleration

First positive peak of the boat’s acceleration and cavity of the rower's acceleration. The blade is fully immersed. Maximal speed of the legs

4

The boat’s acceleration decrease and becomes lower than the rower’s acceleration. This is caused by the increase of the stretcher force, which again becomes higher than the gate force

D4. Rowers’ acceleration

Forces, the rower's and system accelerations increase slowly. Handle speed continues to grow. Legs speed decreases and trunk speed increases

5

The boat’s acceleration again becomes higher than the rowers’ center of mass acceleration. This is caused by a decrease in the foot-stretcher force, which becomes lower than the gate force

D5. Boat acceleration

All forces are decreasing, but the foot-stretcher force is decreasing faster than the gate force, which produces the highest boat acceleration. The rower's and system’s acceleration decrease. The oar crosses the perpendicular to the boat. The handle and trunk achieve their maximal speed.

6

The system’s acceleration becomes negative. The centre of the blade crosses the water level

D6. Blade removal

The handle continues to move towards the bow. The arms achieve the maximal speed. The rower's mass is begins the recovery phase (negative acceleration). Nearly zero boat acceleration

7

Release, end of the drive. The oar handle movement changes direction toward the stern

R1. Arms and trunk return

The moment of inertia transfers from upper rowers’ body to the boat mass. This causes a quick positive peak of boat acceleration and negative rower’s acceleration

8

The seat starts moving toward the stern. This causes an increase of the boat’s acceleration and a quicker decrease of the rowers’ center of mass acceleration

R2. Legs return

The boat acceleration is positive (depending on the stroke rate), but rower’s and system accelerations are negative. The legs speed towards the stern increasing. Arms are nearly strait, trunk crosses the vertical position

9

Rower starts pushing foot-stretcher. The speed of the seat decreases and the boat’s acceleration becomes negative

R3. Catch preparation

Rowers push the stretcher stronger. This causes the boat deceleration, but rowers’ centre of mass starts acceleration. Arms and oars prepare for the blade entry to the water.

 

Figure 9. Micro-phases of the stroke cycle (key event and the following phase). Men’s pair James Tomkins and Drew Ginn, Olympic Champions of Athens Games 2004. Stroke rate 36.5 str/min, video 25 fps, frame number – micro-phase.

 Figure 10. biomechanical parameters and micro-phases of the stroke cycle (M1x, rate 32 str/min). Key events are marked with circles.

During D1 – D2 the rowers push to accelerate their body mass and decelerate the boat, because they have to change direction of their movement from the stern to bow at catch. The quicker these micro-phases, the better. Then, during D3 the rowers accelerate the boat to create faster moving support on the foot-stretcher to further accelerate their bodies. This micro-phase is extremely important for performing effective drive phase but in some crews this phase can be absent. Fast increasing of the handle force is the main condition of its presence.

During D4 the rowers push the stretcher again to accelerate themselves and accumulate the main part of kinetic energy. Effectiveness of this phase depends on the amount of gained boat speed during the previous D3 and fast powerful legs drive. The final boat acceleration micro-phases D5 and D6 utilize more pull by means of trunk and arms work. Forces and total system acceleration decrease during this phase and rower’s acceleration become negative transferring kinetic energy to the boat. This push-pull-push-pull coordination during the drive requires coordination and “boat feel” from the rowers.

Biomechanical variables

Rowing provides an excellent model for biomechanical measurements. The first of such measurements were carried out by Atkinson in 1896. Since then, the biomechanical measurements have become common practice both for research and athlete training purposes in major rowing countries. The main variables of the rowing biomechanics are: the oar angle, force application, boat velocity and acceleration, and body segments movement.

Oar Angle

The horizontal oar angle defines the amplitude of the rower’s movement. The angle is measured from the perpendicular position of the oar relative to the boat axis, which defines zero degree. The catch angle is defined as the minimal negative angle and the release angle is the maximal positive angle. The horizontal oar angle is used for definition of the start of the stroke cycle, which occurs at the moment of zero oar angle during recovery (Kleshnev, 2005).

Table 7. Average oar angles in different categories of rowers at racing stroke rate

Categories

Catch angle

Release Angle (deg)

Total Angle (deg)

Men scull

-66.5

43.8

110.4

Men light scull

-64.5

42.6

107.1

Men sweep

-56.8

34.3

91.2

Men light sweep

-54.3

33.6

87.9

Women scull

-62.2

43.0

105.2

Women light scull

-61.3

42.8

104.2

Women sweep

-53.5

33.4

86.9

 

The total rowing angle can be 4% longer at the lower stroke rate 20-24 str/min. A vertical oar angle is useful for defining of the rower’s oar handling skills. It reads zero degree when the centre of the blade is at the water level and negative downwards.

Forces

The forces in rowing are usually measured at the handle and at the gate (pin).
The handle force can be determined by means of measuring the bend of oar shaft. The point of the handle force application is not certain, especially in sweep rowing, where the rower can pull more with the inside or the outside arm. This can create a problem if the ambitions is to know the handle force itself, but it produces more reliable values of rowing power applied to the handle, because it is calculated using the moment of force (Kleshnev, 2000).

The gate force is measured using specially developed instrumented gates. This method produces more accurate and informative data on the force applied to the boat, but calculation of the power from the gate force is not accurate.

Table 8. The handle forces and rowing power at racing rate in different categories of rowers

Rower’s categories

Maximal Handle Force (N)

Average force during the drive (N)

Rowing power (W)

Men scull

766

405

528

Men light scull

692

360

464

Men sweep

671

331

520

Men light sweep

590

294

425

Women scull

547

286

329

Women light scull

477

253

285

Women sweep

479

238

308


The graph of the force relative to time or horizontal oar angle called “force curve”, which is a valid indicator of rowing technique. Peak force develops earlier in big fast boats and at higher stroke rate.

Body segments input

On average, each of three body segments contributes approximately one third to the total length of the stroke arc (legs a bit more, trunk a bit less). The legs execute their work during the first half of the drive, when the force exertion is maximal. Therefore, the legs produce nearly half of the rowing power (46%); the trunk produces nearly one third (32%) and arms a bit more than one fifth (22%). As higher stroke rates the legs increase their percentage contribution power. Thus, trunk muscles utilize only about 55% of their work capacity during rowing. At the same time, the arms use about 75% and the legs up to 95% of their respective work capacity.

Rowing technique

Rowing styles and efficiency

Rowing styles are defined by movement of two biggest body segments: the legs and the trunk. The most popular attempt of classification of rowing styles was by Klavora (1977), which defines the following three main styles.

• The Rosenberg style is named after Allen Rosenberg, who was the head coach of many USA national rowing teams from 1961 to 1976. This is the most traditional style and inherits developments in technique introduced by the great English-Australian coach Steve Fairbairn in the end of 19th - early decades of the 20th century. This style is characterised by large forward declination of the trunk at the beginning of the stroke, then strong leg extension without significant trunk activation. At the end of the cycle the trunk stops in the deep backward position.
• The Adam style was developed in 1960-s by the innovative coach Carl Adam from West Germany. This style has a comparatively long leg drive, limited amplitude of the trunk and simultaneous activity of legs and trunk during the stroke.
• The DDR style was developed by coaches and scientists of East Germany – the most successful rowing nation in 1970-s. The style is characterised by large, forward declination of the trunk, which begins the drive, followed by simultaneous activity of the legs.

Two main factors, which distinguish these styles are timing (simultaneous or consequent activity of two biggest body segments) and emphasis during the drive (on legs or trunk). These factors can be illustrated as X and Y axes of a quadrant (Figure 11).

The three mentioned styles perfectly fit three quarters of the quadrant. However, a fourth rowing style exists. This style has consequent timing and emphasis on the legs drive. This style may be called the “Grinko style” after the talented Russian coach Igor Grinko who coached World Champions M4x of USSR and then 1990 World champion and 2004 Silver Olympic medalist in M1x Jueri Jaanson. This style inherits the traditions of the USSR school of rowing technique, which produced great rowers in 1950-60 including three times Olympic champion Viacheslev Ivanov.

 Figure 11. Quadrant of rowing styles

The rowing style correlates with the shape of force curve, which affects amount of power generated and blade propulsive efficiency. A sequenced work of the legs and trunk (Rosenberg and Grinko rowing styles) usually produces triangular shape of the force curve and higher peak force and power values (Figure 12). This leads to higher slippage of the blade through the water that causes energy losses. Lower blade propulsive efficiency, however, can be more than compensated for by higher values of force and power produced per kg of body weight. Active use of the trunk produces even more power and the Rosenberg style can be considered as the most powerful rowing style.

Simultaneous work of the legs and trunk (the two German rowing styles) produces more rectangular shape of the force curve, but the peak force and power are lower (Figure 12, b). More even pressure on the blade improves its propulsive efficiency. However, slower and more static character of the legs and trunk work does not allow delivering its optimal power.

Figure 12. Effect of the segments sequence and emphasis on the shape of power curve.

Emphasis of legs or trunks work affects position of the peak force and power. Styles with the legs emphasis (Adam and Grinko styles) allow quicker increase of the force and earlier peak of the force curve. This increases the initial boat acceleration micro-phase D3, improves the temporal structure of the drive and makes it more effective. Styles with the trunk emphasis (Rosenberg and DDR styles) produce more power because of better use of big muscle groups as the gluteus and longissimus muscles. However, these muscles are congenitally slow because they are intended to maintain body posture. This fact together with the significant mass of the torso do not allow for a quick increase of the force and shift the peak of the force curve closer to the middle of the drive, making the temporal structure of the drive less effective.

It is, however, uncommon that these rowing styles are found in their pure form. Most rowers adopt a hybrid style in-between these four extremes. The choice of style depends on many factors including body structure of the rowers. For example, it is unlikely that rowers with short legs will adopt a style that emphasises the importance of a long slide.

Coordination, coaching and feedback

Rowing looks quite simple, but in fact it requires very high coordination and sophisticated motor control. The rower has to coordinate his body movement along with the oar’s 3D movement and to maintain the balance of the boat. The task becomes even more complicated in crews, where each rower has to synchronise his movements with that of other members of the crew. Due to short time of the drive phase (<1 s) and the fast movement of big muscle groups, rowers can not change movement pattern during the drive. They can only evaluate their sensations after completion of each stroke and make corrections for the next one. The coach watches the crew and compares his visual impression with the an ideal model of the rowing technique. He then gives verbal feedback to the rowers, which can have more or less immediate nature: after each stroke, after completion of a bout of training, after a session, a day, or a week. A good coach also asks for feedback from the athletes that help him to evaluate the effectiveness of his actions and to find better methods of technique correction.

Several technical tools have become popular for giving feedback to rowers and coaches:
• StrokeCoach and SpeedCoach ™ provide immediate feedback on stroke rate and boat speed;
• Visual feedback can include videotape and replay after the session or in immediate mode using a personal head mounted display;
• Biomechanical data acquisition systems can measure the force applied by the rower, oar angles and other mechanical parameters (seat and trunk position, etc.).
This equipment looks attractive and are powerful tools for correction of rowing technique. However, it is necessary to understand what needs to be corrected and in what direction. Proper theory of rowing biomechanics is crucial when using technical methods of rowing technique correction.

References

1. Atkinson E. 1896. A rowing indicator. Natural Science. 8, 178.
2. Caplan, N. Gardner, T.N. 2005 A new measurement system for the determination of oar blade forces in rowing. In Proceedings of the 3rd IASTED International Conference on Biomechanics, (ed. Hamza, M.H.) Acta Press, Calgary, Canada
3. Concept 2 web site www.concept2.com/05/oars/vortex1.asp
4. Filter K., 2000. Effect of wind on boat speed. Materials of FISA coaches conference in Seville.
5. Klavora P. 1977. Three predominant styles: the Adam style; the DDR style; the Rosenberg style. Catch (Ottawa), 9, 13.
6. Kleshnev, V. 2000 Power in rowing. Proc. Of XVIII Congress of ISBS, Hong Kong, Vol.II, 662-666.
7. Kleshnev V. 2005. Technology for technique improvement. in: Nolte V. (ed.) Rowing Faster. Human Kinetics. 209-228.
8. Nolte V. 2005. Rigging. in: Nolte V. (ed.) Rowing Faster. Human Kinetics, 125-140
9. Sanderson B, Martindale W. 1986. Towards optimizing rowing technique. Med Sci Sports Exerc; 18 (4): 454-68