There's more to it than making yourself aerodynamic - sportsmen have some very practical reasons for removing their body hair.
Cyclists and Athletes: A slick body slides a lot better so when you inevitably hit the deck at some point in your training schedule, you are less likely to sustain severe grazing from the road or track. If you do hurt yourself, it’s much easier to clean up bare skin and put on dressings. And, importantly, it’s considerably less painful to take these dressings off again. Waxed skin is also much easier to massage which can be surprisingly painful when there is body hair to get tangled up in a therapist’s fingers.
Swimmers: Have followed the lead of dolphins and removed their body hair for years as a heightened feel for the water and less drag in the pool makes for quicker swim times.
Body Builders: These guys work hard and eat hard in order to show off their bodies - so it goes without saying that a body hidden by hair is not ideal. It is also mush easier to apply oils or get an even tan without hair to negotiate