Why do swimmers switch between full body suits and half body suits?

Question

Why do swimmers switch between full body suits and half body suits?

Answer 1

It's my understanding that the new full-body suits are ultra tight you really have to wedge yourself into them (think of women trying to fit into their too small pants).

They also have something of a girdling effect.  Now, for a more straightline stroke, like backstroke or freestyle, where you maintain a fairly straight body position and only really rotate the shoulders, that's not a problem.

Breaststroke and butterfly require a lot of full body undulations with coiling and bending at the waist, which probably wouldn't be possible with the ultra-tight fit of the new suits.

Answer 2

If you notice, Michael Phelps wears full body suits in things like freestyle, but changes to half-body when he swims butterfly.

The buttefly stroke requires the upper shoulders to rise, and sometimes the upper tank will "pull" from the water, causing a minor degree of additional stress on the muscles. In addition, the straps that hold the tank, though very light weight, provide additional stress.

So, fabric the same high-tech fabric that enhances bouyancy, will actually cause miniscule stress in swimming events such as the butterfly.

In a sport where a hundredth of a second can mean the difference between gold and silver, this is quite a consideration.  

Answer 3

it's a personal preference thing.  the full body suits can be rather uncomfortable - they're really tight (they pull in the bumps of the body to make the swimmer more streamlined) & a lot of swimmers prefer the freer half body suits especially for the heats, but will switch to full body for the finals.