The innumerous health benefits of physical activity &exercise for weight loss, general fitness and mood enhancement are well established. Less widely known, perhaps, is that physical exercise reduces the risk of getting breast cancer, improves the survival in breast cancer patients and reduces breast cancer recurrence by helping to reduce the levels of many of the chemicals in our bodies that are associated with the initiation and development of breast cancer. Physical activity further helps the person to feel good and helps prevent breast cancer in women of all ages, especially the post-menopausal women.
World Health Organization (WHO) defines moderate exercise as; 150 minutes per week is estimated to reduce the incidence of breast cancer in post-menopausal women by 20-30%. Around 3.4% of post-menopausal breast cancer cases in the UK have been attributed to lack of physical activity. In other countries estimates are higher; an Australian study suggests 7.8% of post-menopausal breast cancers were a result of insufficient physical activity.
After the initial diagnosis, moderate exercise reduces mortality by an estimated 24% and even as little as one hour of walking per week is of some benefit and as the duration of walk increases the benefits also increase. Exercise can also be psychologically helpful for post-treatment breast cancer survivors; as one study found higher levels of exercise were associated with reduced stress and fatigue, and reduced memory impairment. Moderate intensity exercise and life-long aerobic fitness improves immune cell types.
Even though it is not fully understood how exercise decreases the breast cancer risk, it is thought that exercise helps to reduce body fat and consequently decreases the levels of certain hormones (Estrogen, Leptin and Insulin and growth factors (IGF-1) that are secreted by adipose (fat) cells. High levels of these hormonespromote breast tumor growth and progression. The American College of Sports Medicine guidelines conclude that exercise is safe during and after all breast cancer treatments and improves physical functioning, quality of life, and cancer-related fatigue. The evidence that exercise further helps breast cancer survivors live longer and lead a more active life.
Lecturer, Faculty of Health Sciences