Slimmer Doesn’t Always Mean Fitter

Exercise physiologists agree that if your sport is particularly affected by the tug of gravity — running, cross-country skiing, cycling up hills — you are penalized for excess weight. But that leaves some questions: What is the ideal weight for your sport? And how much difference will it make if you actually achieve it? There have been few direct tests of the body-weight effect, said Hirofumi Tanaka, an exercise physiologist at the University of Texas at Austin. Most of them were done in the 1970s and involved subjects who were asked to run with weights on their backs or ankles. Sure enough, the heavier the people were...

http://www.nytimes.com/2010/02/04/fashion/04best.html?ref=nutrition