A study looked at the results of more than 60 research trials
examining the link between breast cancer risk and exercise. One
thing comes through loud and clear in all these studies: regular
exercise can lower breast cancer risk by about 25% to 30%. The
benefits of exercise were not the same for all women -- the type
and amount of exercise affected the amount of risk reduction. -
Women who had a healthy weight to height ratio -- body mass
index (BMI) -- got more benefits from exercise than women with a
higher BMI. This could be because the protective effects of
exercise were offset by the increase in risk associated with
being overweight. - Older, post-menopausal women; non-white
women; women who have given birth; and women with no family
history of breast cancer got more benefits from regular
exercise. - Exercise seems to lower the risk of hormone-
receptor-negative breast cancer more than it lowers the risk of
hormone-receptor-positive breast cancer. - Vigorous recreational
(not done at work) exercise, such