Link Between Estrogen and Reduced Muscle Pain in Women Studied at UMass Amherst

AMHERST, Mass. - Do women have a natural advantage when it comes to muscle soreness caused by exercise or exertion? They may, because the hormone estrogen cuts down on muscle damage in animals and could serve the same function in humans, according to a University of Massachusetts researcher.

Priscilla M. Clarkson says preliminary research indicates that estrogen prevents some muscle damage and therefore reduces soreness. "The results from animal studies are very clear in showing a link between overexertion muscle damage and the amount of estrogen," Clarkson says.

More research is needed, however, because studies on humans are not as conclusive as those done on animals. A recent study conducted by Clarkson found that women who take oral contraceptives, which contain estrogen, experience less muscle soreness than women with low levels of estrogen in their systems. That study was reported in June in the Canadian Journal of Applied Physiology. A more recent study, however, using a larger sample of 83 women and 82 men found no gender difference in strength loss, stiffness, and soreness after strenuous arm exercise.

Clarkson says studies done with rats clearly show a gender difference with males suffering significantly more muscle damage than females after the same amount of exercise. One possibility is that estrogen stabilizes the muscle membrane and prevents what exercise scientists call "microtears" in muscle tissue caused by vigorous exercise, Clarkson says.

Muscle soreness is a common result of exercise, especially when muscles are extended, and in moderate amounts is considered healthy because it indicates the muscle is growing and getting stronger.

Clarkson is a professor of exercise science and associate dean for academic affairs at the School of Public Health and Health Sciences at UMass.