The various bodysuit manufacturers have advertised very significant performance gains that should result from using their products. It is common to hear the figure 3% used, and in some cases, higher values are proposed (e.g., Speedo in Australia). Among the manufacturers, it is agreed that full-length bodysuits will enhance performance, despite misgivings among the swimming population about their being fitted and of certain shapes. If bodysuits, and their "high-tech" fabrics, have the obvious significant effect upon swimming performance, there should be a general improvement displayed by a swimming population when they are used in a competition.
Dr. Joel Stager, an applied physiology professor in the Department of Kinesiology at Indiana University, uniquely evaluated the effects of bodysuits on competitive performances at the US Olympic Swimming Trials held in Indianapolis in August 2000. Olympic swimming trial times from the past 25 years were used to predict the performances in the just-completed US 2000 Olympic Trials (a power curve was the line of best fit). If predicted times at the meet were similar to those recorded, then no universal performance-enhancer, such as bodysuits, existed. If there was a general improvement above that which could be reasonably expected, then one might propose that bodysuits do enhance performance in line with manufacturers' claims. A comparison of predicted and actual times would serve as an evaluation of any effect derived from bodysuits.
At the US trials, virtually all swimmers had bodysuits made available to them by various manufacturers. Astute observers estimated that 90-95% of contestants used some form of Speedo suits. One could make a compelling case that the trials were a "fair test" of the general effect of Speedo's new suits and fabrics.
Dr. Stager's work can be viewed in detail at http://www.indiana.edu/~kines/trials2000.html. It provides tables and analyses in detail. The data show that there are some events that were better and others worse than predicted (about a two to one ratio). The sizes of discrepancies were so small, that for all but two events, one could assert that performed times matched predicted times.
If one accepts the hypothesis that Dr. Stager's predicted times are "reasonable" estimates for normal swimming progression without bodysuits, or some other performance-enhancing item, some interesting conclusions can be drawn. From this reviewer's perspective, this is what was learned about bodysuits from the US trials.
There is no general beneficial effect of using bodysuits. One gender did not exhibit a benefit over the other, there was no benefit for one stroke over another, and there was no favor for one distance classification over another. The presence of the suits was not associated with any marked deviation ("consistent improvement") in performances displayed at the US Swimming Trials.
Fewer women's than men's events achieved the predicted times. This is important because more women wore Speedo suits than men did, probably because they are forced to wear a torso covering.
Observations of US swimmers' behaviors were strikingly similar to those made of Australian swimmers at their trials. As the US trials progressed, swimmers began to discard the neck to ankle full suits (before the trials few swimmers would embrace sleeved-suits and so they were virtually non-existent). Breaststrokers almost completely discarded them and mostly wore traditional-cut suits in finals, although most of those suits used Speedo's new fabric. Backstrokers and butterfliers did not like below-the-knee suits and males preferred not to cover the torso. Crawlstrokers tolerated the waist to ankle covering more than in the other strokes but still were in a minority. There were few instances of the "self-tailoring" behaviors of the Australians (e.g., cutting off the lower legs, sleeves, or widening the arm apertures), probably because there was a greater variety of available suits in Indianapolis. Generally, as the trials progressed, swimmers became disenchanted with bodysuits and tended to return to styles that are more traditional. Most elite swimmers do not embrace neck-to-ankle, waist-to-ankle, and certainly sleeved suits. That does not mean that some individuals do not like the suits or do not benefit from them, or more tangentially, derive a "placebo" effect from them. The picture is slightly "muddied" by some athletes who are "paid" or "encouraged" to wear the suits.
At the 2000 US Olympic Swimming Trials, there was no suggestion that bodysuits had any beneficial effect on performance or selective factors that differentiate classes of swimmers or their events.
Evidence of any performance benefit, as marketed by swimsuit manufacturers, did not exist at the US Trials. Manufacturer's claims should now be questioned. Certainly, before one of these expensive suits is purchased, much reflection is needed.
When information about these suits was presented at meetings in Athens last year, scientists in the audience asked for and were promised the supporting evidence for manufacturers' claims. Those scientists are still waiting for the evidence. The manufacturer-inspired "hype" surrounding these bodysuits has all the earmarks of a marketing ruse. Buyers are warned.
The observed lack of benefit of the bodysuits does not remove FINA's culpability for allowing them into competitions in the first place. The precedent has been set to allow external items intended to artificially alter performance into swimming races. With the Olympic Games being such a milestone in the sporting calendar, the opportunity exists for the swimming world to reverse the FINA Bureau's gaff, to return to non-performance-enhancing suits, and restore swimming as a "human-factors-only" sport. This could be achieved at the September 2000 FINA Congress in Sydney.