Exercise (Physical Activity)

Women who get regular physical activity may have a lower risk of breast cancer [164-166]. Although not all studies show this benefit, when the evidence is looked at as a whole, regular exercise appears to lower breast cancer risk by about 10 to 20 percent [164-166]. This benefit is seen most clearly in postmenopausal women [165-166].

How can physical activity affect breast cancer risk?

Exercise can help with weight control. For postmenopausal women, being lean lowers the risk of breast cancer [128-130]. And, physical activity may lower estrogen levels in women, which can also protect against breast cancer [167-168,521]. Physical activity may also boost the body’s immune system so that it can help kill or slow the growth of cancer cells [169].

Learn more about body weight and breast cancer risk.

For girls, physical activity may delay the first period until an older age and reduce the frequency of regular menstrual cycles. Each of these can help decrease the amount of estrogen a woman is exposed to over her lifetime [46]. 

Learn more about estrogen and breast cancer risk.

Physical activity and breast cancer survival after treatment

Physical activity and breast cancer survival

Some studies suggest women who are more active after a breast cancer diagnosis have an increased chance of survival compared to less active women [170-174]. One large study showed that survivors who got between three and eight MET hours (roughly one to two hours of brisk walking) of activity a week had a 40 percent lower risk of breast cancer death compared to less active survivors [171]. Women did not need to do intense exercise to get a survival benefit. Activity equal to a 30-minute brisk walk several times a week improved survival. Women who got more activity got more benefit [171].

Combining regular exercise with a healthy diet may further increase survival in breast cancer survivors [175].

Physical activity and breast cancer recurrence

Regular exercise may also lower the risk of breast cancer recurrence [170,176]. Findings from one large study showed that breast cancer survivors who got between nine and 23 MET hours of activity a week (roughly three to nine hours of walking) had a 35 to 40 percent lower risk of recurrence compared to survivors who were less active [170].

Other benefits of physical activity for survivors

Regular exercise has other health benefits for breast cancer survivors. It can increase positive mood and improve physical condition and movement, which in turn, can enhance quality of life [177-180].

Learn more about physical activity and breast cancer survival.

For a summary of research studies on physical activity and breast cancer survival, visit the Breast Cancer Research section.

Tips to increase physical activity

Being active is good for your health, but it can be hard to find time to exercise. Do whatever activities you enjoy most (for example, dancing or gardening) that get you moving. The following tips may help you become more active [181]:

• Use stairs rather than an elevator.
• If you can, walk or bike instead of driving.
• Exercise at lunch with your coworkers, family or friends.
• Take an exercise break at work to stretch or take a quick walk.
• Plan active vacations rather than only driving trips.
• Wear a pedometer every day and increase your daily steps.
• Join a sports team.
• Use a stationary bicycle or treadmill while watching TV.

*Please note, the information provided within Komen Perspectives articles is only current as of the date of posting. Therefore, some information may be out of date at this time.  

Updated 05/08/13

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