Brent S. Rushall, Ph.D.,R.Psy.
San Diego State University

©Sports Science Associates
Spring Valley, California
May 25, 2008

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FINA supposedly is solving the swimsuit problems created by its past indulgence of manufacturers and not swimmers or coaches. The first attempts at deriving answers appear to be unnecessarily cumbersome and incomplete. One is set to wonder as to just how well the FINA decision-makers understand the problem. Below are three aspects of the problem that have been missed or subverted over the recent addition of by-laws to Rule GR 5.


It is possible that the rigid structure of the "straight-jacket" bodysuits aids performance by helping swimmers to conserve energy.

In a free-swimming individual, postural muscles and metabolism have to be used to hold the swimmer in streamlined alignment. The post-2007 suits now do this for the swimmer relieving him/her of the metabolic cost of sustaining a posture and releasing that saved energy as further resources for propulsion. In any stroke that requires a rigid posture, a greater amount of energy would be available for swimming effort.

There is an added advantage to the rigidity in strokes for which that postural feature is appropriate, although it is not exactly clear as to how this advantage enhances swimming performances. The fixed device offers an external surface against which movement segments could act. This is perhaps best illustrated by an analogy of sporting movements working against different surfaces. When running in sand, the absorption of some of the developed muscular force by the moving surface results in only a partial return of effort to the athlete in accordance with Newton's Third Law. Slow running performances result. When a runner thrusts against a non-giving surface (e.g., shoe-spike-anchored foot placement on a rebound track) the reaction force is much greater producing faster running.

When swimming suits were "soft", all anchor points for segment movements were produced by muscles holding joints and bones in fixed positions, the level of fixation depending on the neuromuscular skill and fitness of the individual. Now, the rigid suits do that for a number of movement segments in the swimmer. This produces a distinct advantage for those athletes who previously displayed a technique fault from poor postural control (e.g., hip sway; discrete hip and shoulder rolls) and unnecessary movements that caused performances to be less than optimal.

Consequently, with the post-2007 bodysuits now performing most of the postural requirements that were previously required of swimmers, the released capacities can be used to improve the magnitude and/or persistence of energizing forces in swimming races resulting in performance enhancements. This function is one good reason that the current structured bodysuits should be banned from competitive swimming because they now relieve the swimmer of natural function that was involved in racing before their introduction.

Since the post-2007 bodysuits alter the way an athlete swims and seemingly causes a change in energy cost, are they not devices changing the swimmer as do fins and paddles?

Rule Application

Previously in competitive swimming if an athlete wore a supportive body or limb covering, a disqualification would result. Supportive coverings would be useful in conditions where an injury had occurred outside of the pool (e.g., a muscle strain produced in weight-room work). At competitions, swimmers used to be screened for any additional covering that exceeded the assumed minimized requirements according to the rules. Apparently, modern swimming has altered that previously strictly-enforced application of the rules. Modern bodysuits serve a somewhat similar function to tight bandages on slightly-injured muscles in that they enhance performance or more appropriately, reduce performance decrement. That has occurred despite there being no change in the sport's rules. This alteration in rule application has added to the chaos that surrounds the sport and its acceptance of performance-enhancing equipment (body coverings).

Bogus Buoyancy

FINA rules [1] prohibit devices that aid buoyancy. However, FINA has ignored the new body coverings as being devices instead relying on their own chosen semantics of deeming them to be swimsuits and thus governed by Rule GR 5 [despite manufacturers advertising them as performance-enhancing, buoyancy-assisting equipment][2] . FINA hastily formulated new by-laws for Rule GR 5 that are supposed to take care of the current swimsuit problem. However, haste has made waste in that the understanding of the problem appears to be deficient which calls to question the level of competency of the decision-makers. The way FINA is now testing for buoyancy is unacceptable when considering the potential for enhancing swimming performances. This weakness reflects on the deficiencies of the present FINA administration's decision-making.

Although neoprene and polyurethane have been accommodated recently by FINA, despite having set the precedent of banning neoprene in 1988, FINA boasts that testing is now in place to evaluate the buoyancy of swimming suits (Rule GR 5 Exhibit 2). Suits are taken and measured for their flotation qualities (termed "intrinsic buoyancy"). That is done without any regard to the interaction of the suit and swimmer.

Anyone who has worn a comfortable neoprene wetsuit for snorkeling or scuba diving can relate to the experience of water seeping in between the skin and suit to fill air pockets and eventually being warmed to a comfortable level. That occurs because the neoprene suit is too loose to be watertight. If the suit was very tight even at its boundaries (e.g., the neck, wrists, and ankles as occurs with "drysuits") no water would seep in nor would trapped air escape.

With the constricting nature of the recent bodysuits, few swimmers report any sensation of water seeping in – they are too restrictive to allow that to occur. Thus, a non-buoyant-in-isolation bodysuit could trap air against the body when it is worn by a swimmer, something that its not evaluated by testing the suit in isolation. That trapped air would improve a swimmer's buoyancy and enhance performance. The amount of enhancement would be dependent upon the volume of trapped air. This phenomenon of interaction between the suit and swimmer is termed "functional buoyancy".

The recent FINA by-law of Rule GR 5 (c bullet 3) states:

Air trapping effects. The swimsuit/material shall not be constructed to or include elements/systems which create an air/water trapping effect (tubing, channels etc) during use.

There is no test yet employed to evaluate this feature. What is disturbing is that the examples of "tubing, channels, etc". do not really capture the major aspect of air trapping that occurs with impermeable materials, which involves the contours and crevices of the body that are covered but not followed by bodysuit coverings. That aspect needs to be accommodated in the rules.

Thus, measuring swimsuits in isolation for buoyancy in no way fully determines the potential of the device to enhance performance through functional and/or intrinsic buoyancy. What needs to be tested is the effect of the suit on swimmers. That can be done simply by using underwater-weighing methods. The buoyancy of a swimmer can be measured with and without wearing a suit and the differences determined. The true potential for buoyancy-assistance of the suiting-device would then be revealed.

This problem could be alleviated simply by adopting criteria that establishes fabric porosity (permeability) and absorption. With standards set that prevent air being trapped under the suit (it would escape because of porosity) or intrinsic buoyancy (the fabric would absorb water) then the enhancement effects of bodysuits would be prevented, no matter what their shape or coverage. However, the complicated and dubious decisions that FINA has inflicted upon the swimming community have failed to resolve the performance-enhancement qualities of suits. Faulty logic and a failure to understand what happens to swimmers in water indicates the paucity of knowledge that has been employed in recent FINA decisions.

Until the structure, rule application, and functional buoyancy problems are solved, unfair competitions will be sanctioned by FINA.



  1. Rule 10.7 states: "No swimmer shall use any device that may aid his speed, buoyancy, or endurance during a competition (such as webbed gloves, flippers, fins etc). Goggles may be worn."
  2. "Equipment" is a synonym for "device" in many English thesauruses seemingly making the new suits also appropriate for considerations involving Rule SW 10.

Return to Table of Contents for The Bodysuit Problem.

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