This is a question many athletes, coaches, and trainers would like to have the answer to. We simply don't know. Some studies have shown that type and number of muscle fibers may have something to do with it. If you take a muscle and cut across it, you'll have what's called a cross-section. Special X-ray tests can do this with a computer that then counts the muscle fibers and measures their size.

But even this doesn't seem to be the entire answer. Some individuals with the same number and size of muscle fibers are still more powerful than others. There must be other issues at hand. Perhaps body metabolism or lung capacity makes a difference. Some men may produce more lactic acid in the muscles taking more time to repair and recover between events.

Researchers have questioned the role of nutrition and diet on muscle performance. Fluid content and hydration have also been studied as a source of greater muscle power. As testing technology improves we may have better ways to examine this question in the future.