Produced, edited, and copyrighted by
Professor Brent S. Rushall, San Diego State University
Volume 3, Number 2: April 23, 1996


[This article was formerly printed in the New South Wales Swimmer, 9(13), 8-9, 1992. Given the demands placed on Carlile and Ryde swimmers, it is still very relevant for today's coaching.]

There is an explosion of swimming research occurring. The implications for coaches are quite staggering as old ideas are refuted and new procedures suggested that will markedly alter the conduct of swimming training and athlete handling. From time to time I will attempt to bring some of the more general implications to the attention of SWIMMER readers not involved with coaching.

One of the most intriguing findings has to do with performance drop-offs during training. It has commonly been thought that most deteriorations are caused by lack of motivation or overtraining. The former is easily identified if it is accompanied by late arrivals at training, missed training session, and frequent negative comments about the sport. The second is something that gradually creeps up on the swimmer and so is not as easily identifiable. However, when a swimmer is well into an overtrained state it is obvious that it has occurred because all short-term attempts to rectify it prove to be futile.

It has recently been found that many performance breakdowns are caused by neither of these two popular attributions. The more likely explanation has to do with the availability of fuel for exercise (glycogen) in a swimmer's body. During heavy training, swimmers can burn in excess of 5,000 k/cal per day. That is more than a top-flight marathon runner will burn in a race. The nature of swimming, the body being water-cooled and supported, makes it easier to work harder than in many other sports. This leads to the problem of a swimmer's body not being able to fuel high workloads.

If a swimmer does not have sufficient stored energy, there is the possibility that protein will also be used to fuel exercise. If that occurs, then a major complication occurs, particularly in growing athletes. A protein insufficiency leads to an inability to improve performance, a failure to adapt to training, and the slowing of recovery between training sessions. There also is the potential for growth to be halted. Protein is required to assist in the way a swimmer responds to training.

What this means for the swimmer is that attention has to be paid to the type and amount of diet. There are several changes that have to be made in a hard-training swimmer's regimen.

  1. Before, during, and after training, not only should water be consumed to avoid dehydration, but so should some carbohydrate supplement. The best form is to take both in the same drink. There are several commercial products available in Australia that fill this role admirably. This will promote glycogen replenishment.

  2. Increase the amount of complex carbohydrate in the swimmer's diet. Greater portions of pasta, rice, potatoes, and whole-grain breads, among other options, should be included. To help in the absorption of carbohydrates an effort should be made to reduce the amount of fats in the diet. Feeding in this manner will promote glycogen replenishment.

    The major problem with getting sufficient carbohydrate is being able to consume the necessary volume of food. That is why the bulk of the diet has to be complex carbohydrates. Excesses of other foods will restrict the intake volume.

  3. To prevent protein deficiency, it is wise to include meat, poultry and fish quantities in the realm of 2 gm/kg of body weight. This will ensure that the swimmer can repair and restore the effects of training and also grow naturally. Feeding in this manner will promote adaptation to training. The value of 2 gm/kg is derived from German research and is in excess of the popular dietitians' recommendation of 1 gm/kg.

  4. A balanced diet is always desirable. Consuming the valuable nutritional features of all the food groups is essential. However, because of the demands of swimming training it is necessary to supplement the normal diet with abnormal volumes of complex carbohydrates and protein.

Further details on these matters can be obtained from a certified coach or editions of the NSWIMMING Coaching Science Bulletin.

What has to be realized is that in the past there has not been enough attention paid to the diet and energy replenishment of swimmers. It now seems that these are more important for contributing to performance deterioration than the more commonly ascribed causes. It is in a swimmer's best interest to ensure that adequate fuel is available for training. If there is depletion, then the best training program and coaching in the world will not induce improvement. The body is just not capable of responding appropriately in an adaptive manner.

During a week of training, it is possible that glycogen and protein insufficiencies arise because of accrued inadequate replenishment. The first few days may be tolerated because sufficient stored glycogen is available. With each successive day reserves are depleted and not restored because of dietary inadequacy. Consequently, as the week progresses performances worsen and improvements become inhibited. Proper feeding may be a means of increasing the volume of good swimming that is performed each week.

It is now appropriate to consider fuel and protein insufficiency as the first possible cause of performance deterioration during prolonged periods of training.

Return to Table of Contents for the Carlile Coaches' Forum.