Why is it that sometimes male swimmers wear tops and sometimes they don't - when racing?

Question

Why is it that sometimes male swimmers wear tops and sometimes they don't - when racing?

Answer 1

the fastskin bodysuits only hav a life of about 24-36 hours. They are 500$!!!!! the more u wear them the more worn out they get and the slower they get. The technology of the full body suits make you go faster. but, still, some prefer the leggings. Also, the jammers and leggings are 100s of dollars less, so its also common sense.  

Answer 2

its all preference. if they ike the body suiit better then just the legs then thats what they wear.