Research shows a link between exercising regularly at a moderate or intense level for 4 to 7 hours per week and a lower risk of breast cancer. Exercise consumes and controls blood sugar and limits blood levels of insulin growth factor, a hormone that can affect how breast cells grow and behave. People who exercise regularly tend to be healthier and are more likely to maintain a healthy weight and have little or no excess fat compared to people who don't exercise.
Fat cells make estrogen and extra fat cells make extra estrogen. When breast cells are exposed to extra estrogen over time, the risk of developing breast cancer is higher.
Steps you can take
Exercise is such an important part of daily life that the United States Department of Agriculture said that all people should meet the Physical Activity Guidelines for Americans in the Appendix of the 2015-20 Dietary Guidelines for Americans. The American Cancer Society recommends that women who have been diagnosed with breast cancer exercise regularly (about 4 to 5 hours per week) to improve their quality of life and physical fitness, as well as to reduce the risk of developing new cancers. Research shows that women who exercise the equivalent of walking 3 to 5 hours per week at an average pace after being diagnosed with breast cancer may improve their chances of surviving the disease.
Start slowly: The first thing to do is to talk to your doctor and possibly a certified fitness trainer about a safe and sensible plan designed specifically for you and your needs and physical abilities. It's also a good idea to talk to your doctor about a healthy weight for your age, height, body type, and activity level.
You may want to start gradually, maybe walking for 15 minutes a day and then slowly increasing the amount of time you spend exercising, as well as the intensity level of each session. You may need months to work your way up to 5 hours a week, but that's OK.
If you're not sure how to start exercising, you might want to visit a gym or make an appointment with a certified personal trainer to learn about different types of exercise. Some people prefer exercising in their homes using videotapes or DVDs. Others find great joy in gardening or building things, as opposed to organized exercise. Some people love being part of a team and playing soccer or baseball. Walking or jogging with a friend is a great way to socialize AND get the benefits of exercise. Dancing to great music is great exercise. With so many different ways to move, you're bound to find a way to exercise that suits your personality and schedule. If you can find one or a mix of exercises that you think are fun and not boring, you'll be much more likely to stick with it.