Many studies have shown a link between exercise and a lower risk of being diagnosed with a first breast cancer or breast cancer coming back (recurrence). As a result, the American Cancer Society and many doctors recommend that women who’ve been diagnosed with breast cancer exercise regularly -- about 4 to 5 hours per week at a moderate intensity level.
A study suggests that women who exercise for more than an hour a day have about a 12% lower risk of breast cancer compared to women who don’t exercise. This link between lower risk and exercising more than an hour per day applied to women of any age and weight. In other words, it didn’t matter how old the women were when they started exercising or how much they weighed -- they still got risk reduction benefits.
The research was presented at the 9th European Breast Cancer Conference on March 20, 2014 in Glasgow. Read the abstract of “Physical activity, hormone replacement therapy and breast cancer risk: A meta-analysis of prospective cohort studies.”
This study was a meta-analysis -- a study that combines and analyzes the results of many earlier studies. In this case, the results of more than 4 million women from 37 studies on exercise and breast cancer risk published between 1987 and 2013 were analyzed.
More than 114,100 breast cancers were diagnosed in the studies:
- 4,300 were diagnosed in premenopausal women
- 31,500 were diagnosed in postmenopausal women
- 78,300 were diagnosed in women whose menopausal status wasn’t known
The researchers compared women who exercised the most -- more than an hour per day of vigorous exercise -- to women who exercised the least and found that women who exercised the most had a 12% lower risk of breast cancer.
Many studies have shown a link between taking hormone replacement therapy (HRT) and a higher risk of breast cancer. So the researchers also wanted to know if taking HRT affected how much exercise lowered breast cancer risk. They found that taking HRT seemed to cancel out the risk-lowering benefits of exercise. It’s important to know that if you’ve been diagnosed with breast cancer, you should NOT take any type of HRT.
If you’re busy with work, household chores, and family matters, finding more than an hour a day to exercise may seem impossible. Still, other studies have suggested that it’s consistency that counts. Doing some type of exercise every day -- even if it’s for less than an hour -- is better than doing nothing.
It may help to break up the exercise into 20- or 30-minute sessions that add up to more than an hour over the course of the day. Walking is a great way to start. Maybe you walk 30 minutes before going to work and another 40 minutes on your lunch break. You can add a few more minutes of walking by parking farther away from your building or taking mass transit. Make plans to walk with a friend after work -- you’re more likely to stick with exercise if someone else is counting on you. Plus, you can socialize and release the day’s stress.
Along with a healthy diet and lifestyle choice, regular exercise is one of the best things women can do to keep the risk of a first-time breast cancer or recurrence as low as it can be. This study adds to other research suggesting that exercising every day reduces breast cancer risk more than exercising once or twice a week. Regular exercise also helps keep your physical and mental health in top shape. No matter how old you are, it’s never too late or too soon to get moving.
Visit the Breastcancer.org Exercise section for tips on exercising safely and how to stick to an exercise routine.