Exercise Helps Prevent Breast Cancer
Studies Show Exercise May Lower Risk and Help Those With Breast Cancer Cope
Family History of Breast Cancer
Most had no family history of breast cancer, including the women with breast cancer themselves. While family history increases breast cancer risk, most patients don't have a family history of the disease.
During the 40-minute phone interview, the women noted whether they had participated in the following activities at some point in their lives since age 14: jogging/running, bicycling, calisthenics/aerobics/dance, racquet sports, swimming, walking/hiking for exercise, or other strenuous individual or team activities.
Most women, whether or not they had breast cancer, reported getting up to three hours of weekly strenuous exercise at some point since age 14.
But 461 women without breast cancer, and 332 with breast cancer, said they had exercised strenuously for more than six hours weekly at some point since age 14 -- typically when they were in their teens and early 20s.
23% Less Likely
The women who reported getting more than six weekly hours of strenuous recreational physical activity were 23% less likely to have breast cancer, compared to sedentary women, the study shows.
Exercise appeared to benefit women, regardless of age.
But the benefits were only seen in those with no family history of breast cancer.
The results held after adjusting for other breast cancer risk factors.
The study doesn't prove that exercise single-handedly prevented breast cancer or show how exercise may lower breast cancer risk.
The effects of exercise on hormones and weight may help, the researchers suggest.
They note that they don't know if the women accurately recalled their workout habits.