[sci.bio] body fat in swimmers

don@utzoo.uucp (Don Jackson) (10/07/88)

Don Gillies (gillies@cs.uiuc.edu) writes:
>In general, world-class swimmers have a higher percentage of body fat
>than almost every other type of endurance athlete. Why is this?

There is a simple explanation for increased body fat in swimmers.
Fat increases the bouyancy of the swimmer allowing for more stroke
energy to be expended in propelling the swimmer forward rather than
using energy (and time) to maintain the swimmer at the surface.
Some optimal level of body fat should exist which increases the
bouyancy while not sacrificing speed due to increased drag. Marathon
runners do not need the additional baggage that increased body fat
would cause and their performance would likely suffer as a result
of having increased body fat concentrations.

Additionally, for long-distances in cool water, increased body fat
would provide additional insulation and minimize hypothermia.