Highlights from the USA Swimming Conference on Sports Medicine and Sports Science in September 2003: Part II

By Jessica Seaton, D.C.

A Comparison of Body Density and Center of Buoyancy in Competitive Swimmers and Full Body Suits presented by Richard Hinrichs, Ph.D., Arizona State University. Previous studies had shown that the Speedo Fastskin suit decreased the passive drag effect in the water. This current study looked at full-body suits by Adidas, Arena, Nike, Speedo, and TYR, and compared them to a normal lycra suit (Speedo). Except for Adidas, all were full-body suits without arms. The Adidas suit had arms. All the suits were bought, not donated. The subjects consisted of 14 males and 16 females, with ages ranging from 18 to 36 years. All were swimmers.

The researchers first studied how the suits affect buoyancy in general. In men, all suits except the TYR were more buoyant than a conventional suit for the first minute. After 2 minutes only the Adidas, and Arena were more buoyant than the conventional suit, but less so than they were during the first minute. For women there was less variation than for the men. These suits were about one tenth as buoyant as a wet suit.

The second area the researchers explored had to do with a shift in the center of buoyancy. If the gravitational force and the center of mass are off center, the swimmer’s feet tend to sink. Conversely, the closer together these are, the better one floats. Anecdotally many swimmers remark that their legs feel like they are floating in the suits with legs. For the men, who in general don’t float as well, TYR was the only suit that provided an advantageous shift in the center of buoyancy. Women usually float better than men. The only suit that showed a significant statistical advantage for the women was the Adidas.

Strength, Power, and Swim Performance presented by Joel Stager, Ph.D. Joel Stager run the Councilman Research Lab at Indiana University, the best known swimming research facility in the country. He presented some of the results of a seven-year study focusing on sprinting, especially the 50 freestyle. Some of the highlights from his exciting and detailed talk included:

Power (force times distance over time) per stroke is the strongest determinant of maximum swimming velocity.
Men and women are similar in how they apply power per stroke, but men have more power and therefore faster velocity.
Power differences between individual swimmers are more important for men in their swimming performances. Non-power measures account for more of the differences in women’s performances.
Body composition, as far as percentage fat, is not important as far as sprint performance (a correlation was not found). However, muscle mass is important: more muscle is positively correlated with more power, especially for men.
Vertical jump ability does not correlate well as a velocity predictor.
By age 13 or 14 boys and girls start differing a lot in their power.
Taller swimmers with longer arms are generally faster, but more so for men than for women.
Kicking may be more important than we think.
Dry land strength training did not necessarily result in an increase in power in the water. Working with the research center’s modified power rack did increase in-water power. However, this training only starts becoming effective at 14 for girls and at 15 for boys.
The problem with training in a drag suit is that the swimmer usually alters the stroke and swims more slowly. This defeats the purpose of the training, because to swim fast, the swimmer has to practice fast swimming.

Science and Medicine in Research and Training presented by Jack Daniels, Ph.D. Dr. Daniels was a very entertaining speaker, with many stories related to his years as an Olympic athlete, coach, and scientist. He began by talking about what makes a champion: great ability (anatomical, biomechanical, and physiological) and high intrinsic motivation. Beyond these qualities, an athlete needs opportunities, such as facilities, competition, equipment, the ability to travel, direction from a positive coach, and good program. He explained that at some point you get as fit as you’re going to get. After that getting faster means improving your economy in the water (technique). In contrast to running, for swimmers to swim faster they must expend a lot of energy. Conversely, a swimmer only needs to slow down a little in order to save a lot of energy.

The purposes of training are 1. to increase the available energy (better vascularization of the muscles, stronger heart), 2. improve speed (power, technique), 3. improve economy (technique), and 4. improve endurance. Every workout should have a purpose, i.e., improving endurance, speed, or economy.

Training and competing require focusing on the task at hand (concentration). He encouraged swimmers to trust success and question defeat, and he cautioned you learn more from losing a race than winning one. Accept your very best as your norm. As a final ingredient of success, Dr. Daniels mentioned luck!

Disordered Eating—Psychology versus Nutrition, Clinical Implications, and Identification and Coping Strategies for Coaches presented by Kristen Martin and Rebecca Morgan, M.D. These speakers work primarily with female college students, but emphasized that disordered eating begins before college. While it is not primarily a problem of masters swimmers, it may have been a problem for some when they were younger, or they may the parents of a child with a potential eating disorder. Eating disorders, such as anorexia nervosa or bulimia, begin as disordered eating. Disordered eating can be any irregularity, from avoiding certain foods (i.e., carbohydrates), to eating only one meal per day. There is a spectrum from disordered eating to eating disorders. USA Swimming published a booklet on eating disorders/disordered eating authored by a task force of health professionals involved in swimming.

Jessica Seaton, D.C. is a chiropractic orthopedist in private practice in West Los Angeles. She swims with West Hollywood Aquatics and is chair of the USMS Sports Medicine Committee. She can be reached at (310) 470-0282 or Jseaton@aol.com.