Re: How do the new body suits for olympic swimmers work?

Hi Mr. Elterman,

I believe that you are referring to the new "fastskin" body suits. They are also known as "shark skin" suits. The suits are made by a couple of manufacturers, but the ones made by Speedo are supposed to be on the cutting edge. The suits are specially fitted to each athlete and are very tight. They are modeled after shark’s skin. Sharks have v-shaped ridges on their skin which are called dermal denticles. They claim is that this design results in less drag. I could go into coefficients of friction, but I do not know how fluids might affect them. However, it must produce less friction with the water than skin.

Sharks’ denticles remain the same size as the sharks grow. They grow additional denticles to cover their body. Water in contact with these denticles seems to encounter less friction than regular smooth skin. This effect reminds me of golf ball dimples. It was found that golf balls with dimples traveled faster than those without. It was as if the golf ball was smaller in diameter. The effect only works on small balls traveling at typical golf ball speeds. I believe that the golf balls had diameter restrictions, so that they could not just make the ball smaller. Someone in flow dynamics might be able to explain these unusual effects. [note added by MadSci Admin: There are some existing answers in our archives dealing with golf ball dimples.]

Speedo claims that the suit can decrease times up to 3%. This claim has been backed up somewhat by the experiences of suit users. However, I could not find any hard evidence to back up the claim. Given all of the variables of human performance, I am not sure there is any experiment that they could use. Perhaps they could come up with the water equivalent of a wind tunnel. Cyclists have used wind tunnels to find the best bike design and rider positions. Interestingly, at least some of the bikers’ positions have been outlawed after their successful use.

There has been a big controversy over these suits. At first they were only provided to swimmers sponsored by Speedo. Kieren Perkins, a world record holder swimmer, claimed that the suit gave Speedo swimmers an unfair advantage. He also said that the suit has created a whole new category of swimming. He had tried to obtain a "shark skin" suit, but had been denied because he was not sponsored by Speedo. A few days after the race, Speedo decided to make its suit available to everyone.

The suit is legal according to FINA’s rules. FINA stands for La Federation Internationale de Natation Amateur. I think it translates to the international federation of amateur swimming. However, John Coates, the Australian Olympic Committee president, has warned swimmers that they may risk losing their medals if they wear the suit. This may happen if a swimmer without a suit protests. The argument will then go to FINA. They may rule in favor of the suit, but the swimmer can appeal. Coates says that he hopes swimmers will not wear the suit because of the risk involved.

I just found something referring to a type of body suit that did not mention anything about shark skin. I am somewhat confused. It seems like the fastskin, shark suit and body suit are all the same thing, but I am not positive. This suit goes all the way down to the ankles and looks similar to the suits worn by speed skaters. This suit claims to reduce muscle fatigue and improve the accuracy of movement by 12 percent. I could not find any information on how it does this. It is coated with Teflon to avoid water retention. My guess is that they are all body suits with different features. The Speedo has the shark-like texture, and the Adidas suit has Teflon. I hope that this answers your question and that I did not confuse you terribly.

If you have any more questions please write back to the MadSci Network. Thanks.

Kevin