Phys Ed: What Exercise Science Doesn’t Know About Women

(..)Scientists know, of course, that women are not men. But they often rely on male subjects exclusively, particularly in the exercise-science realm, where, numerically, fewer female athletes exist to be studied. But when sports scientists recreate classic men-only experiments with distaff subjects, the women often react quite differently. In a famous series of studies of carbo-loading (the practice of eating a high-carbohydrate diet before a race), researchers found that women did not pack carbohydrates into their muscles as men did. Even when the women upped their total calories as well as the percentage of their diet devoted to carbohydrates, they loaded only about half as much extra fuel into their muscles as the men did.

Why women respond differently seems obvious. Women are, after all, awash in the hormone estrogen, which, some new science suggests, has greater effects on metabolism and muscle health than was once imagined. Some studies have found that postmenopausal women who take estrogen replacement have healthier muscles than postmenopausal women who do not. Even more striking, in several experiments, researchers from McMaster University in Canada gave estrogen to male athletes and then had them complete strenuous bicycling sessions. The men seemed to have developed entirely new metabolisms. They burned more fat and a smaller percentage of protein or carbohydrates to fuel their exertions, just as women do.