Breast Cancer Prevention: How To Stay Active

In Part Two of our prevention series, we highlight the importance of exercise in breast cancer prevention.

Do you have to exercise to lose weight?

Diet alone, may help you burn off fat, but without exercise to keep muscles strong, it may also eat away at lean muscle mass. Regular exercise will keep the muscle strong and active and sends a signal to the body not to break down muscle tissue for energy, making fat a more attractive energy source.

You don’t have to be a body builder, a marathon runner or own a gym membership to stay metabolically fit. The U.S. Department of Health and Human Services offers exercise recommendations for both aerobic exercise (walking, swimming cycling, etc.) as well as muscle strengthening also known as resistance exercise. While resistance training will not help you lose weight, it will improve body composition by increasing muscle mass and increase Basal Metabolic Rate, which we discuss in more detail below.

Children ages 6-17: At least 60 minutes of exercise a day that includes aerobic and muscle strengthening 3 times a week;

Adults 18-64: 150 minutes (two and half hours) a week of moderate-intensity, or 75 minutes (one and a quarter hours) of vigorous-intensity aerobic exercise plus muscle strengthening that involves all major muscle groups 2X/week;

Over age 65: Follow adult guidelines

How is metabolism related to weight loss?

Metabolism refers to the process that converts food into energy. Energy can be used while active, but is also used when the body is at rest. These “quiet” functions include breathing, digestion, and blood circulation, all those things that keep the body functioning. The energy our bodies use while at rest is called the basal metabolic rate (BMR).

A person’s BMR is based on a number of factors, including genetics, sex, age, body size and body composition– particularly the ratio of muscle to fat.  Muscle burns more energy at rest than fat does, so a physically active person with little body fat will have a higher BMR than a sedentary person, even if he/she isn’t overweight, but has a low muscle: fat ratio.

The best way to increase BMR and thus maintain weight loss is by altering body composition.  According to the American College of Sports Medicine, 250 minutes of physical activity a week can help maintain weight.

Should I exercise if I am in treatment for breast cancer?

There are many benefits of exercise for those diagnosed with breast cancer, both during and after treatment and particularly for older women. In addition to the benefit in helping to lose or maintain a healthy weight, exercise after breast cancer can ease the side effects of chemotherapy, such as fatigue and anxiety and improve mood, self-esteem, and daily functioning.

Research by BCRF investigator Melinda Irwin and others has shown that regular exercise after therapy ends can decrease the risk of recurrence of some breast cancers and improve overall quality of life. You can read more about physical activity guidelines for cancers survivors and learn what questions to ask your oncologist at the American Society of Clinical Oncology’s Physical Activity Tips for Cancer Survivors.