Regular physical activity helps improve your overall physical, emotional and social health and well-being. Another important reason to get more active is that this can lower your risk of breast cancer by as much as 25–30 per cent.
How does physical activity reduce breast cancer risk?
It is not clear whether the reduction in breast cancer risk is related to physical activity alone or to a combination of factors. Women who are physically active may also be more likely to eat a balanced diet, have a healthier body weight, quit or avoid smoking and pursue other healthy behaviours.
Research shows that body weight plays a role in breast cancer because fatty tissue produces hormones and growth factors that may promote cancer development. Research indicates that the level of these hormones produced by the body can be modified by physical activity.
Regular physical activity is beneficial for women of all ages, before and after menopause. It’s never too late to start: the benefits of regular physical activity exist even when you start later in life.
How much is enough?
Guidelines from the Canadian Society of Exercise Physiology recommend the following for adults aged 18–64:
Get a minimum of 30 minutes per day or about 2.5 hours per week of moderate-to-vigorous aerobic physical activity, for example brisk walking, cycling, swimming, taking an exercise or dance class, or cross-country skiing.
Choose physical activities that you enjoy and will be more likely to continue. The activities you choose can be as simple as taking a brisk walk for 30 minutes, five days a week. Whatever you choose, aim to push yourself to break a sweat and breathe harder.
If you are already active for 30 minutes a day, try to work your way up to 60 minutes.
The activity can be broken up throughout the day in 10-minute bouts, at a minimum.
Add muscle and bone strengthening activities on at least two days per week. This includes brisk walking, jogging, or lifting weights.
If you are not a healthy weight, even a small weight loss may lower your risk of breast cancer. The best weight-loss formula involves low-to-moderate intensity activity over a longer period rather than short, intense bursts.
You may be more active than you think
Physical activity adds up and can include things like the following:
Getting off the bus a couple of stops early and walking to your destination
Taking the stairs instead of the elevator
Taking a brisk walk after meals
Raking leaves or gardening
Taking regular stretch breaks throughout the day
Walking the dog.
Playing with your children
Canadian Society for Exercise Physiology. (2011). Canadian Physical Activity Guidelines. Accessed July 31, 2011.
Friedenreich, C M & Cust, A E. (2008). Physical Activity and breast cancer risk: impact of timing, type and dose of activity and population subgroup effects. In British Journal of Sports Medicine 2008; 42: 636-647. Accessed October 12, 2011.
Johns Hopkins Breast Center – Artemis Bulletin. (October 2003). Exercise and Breast-Cancer Prevention: It's Never Too Late to Start. Accessed July 31, 2011.
Public Health Agency of Canada. Physical Activity Guidelines. Accessed July 31, 2011.
National Cancer Institute. (2008). Delving Deeper into Exercise and Breast Cancer Prevention. In NCI Cancer Bulletin, Oct 21, 2008, Vol. 5, No. 21. Accessed July 31, 2011.
American Cancer Society. (2006). Guidelines on Nutrition and Physical Activity for Cancer Prevention. Accessed July 31, 2011.