They say exercise is medicine. And that’s certainly the case when battling breast cancer.
“Getting and staying active is one of the best things that anyone with breast cancer can do,” says Leslie J. Waltke, physical therapist and founder of the Waltke Cancer Rehabilitation Academy, which trains oncological health care providers.
In fact, 2020 research published in the Journal of the National Cancer Institute shows that exercise significantly improves survivability and lowers the risk of recurrence in people diagnosed with breast cancer. While the exact mechanisms aren’t known, a 2019 animal study published in Frontiers in Oncology suggests that when performed during treatment, physical activity can heighten anti-tumor activity within the immune system.
Importantly, regular physical activity directly combats many of the side effects of cancer-directed treatments including chemotherapy, radiation, hormonal therapies and surgery.
For instance, according to Dr. Roshani Patel, a breast surgical oncologist with the Dartmouth-Hitchcock Norris Cotton Cancer Center in Manchester, New Hampshire, exercise reduces:
- Nerve damage.
- Arm swelling.
- Muscle weakness.
- Scar tissue.
All of these can occur during the course of breast cancer treatments, she says.
The pectoralis, or chest, muscle is the most commonly affected during breast-cancer-directed treatments, with mastectomies occasionally even requiring cutting the muscle. During breast reconstructions in which a person’s own tissues are used, pieces of the latissimus dorsi muscle in the back and the rectus abdominis (six-pack muscles) are resected and placed in the chest. Even without the underlying muscle being affected, incisions and the removal of necessary skin can reduce the amount of slack provided to the shoulders, limiting range of motion and function. Scar tissue is another concern that can limit mobility.
Non-invasive cancer-directed treatments can also negatively impact musculoskeletal health and function. For example, some chemotherapy drugs can cause connective tissues to thicken and harden as well as bone strength and muscle mass to decline, Waltke explains. Low levels of muscle are linked to reduced survivability from breast cancer, according to 2019 JAMA Oncology research. Together, this makes the chest and shoulders particular areas of concern during breast-cancer-related physical therapy, she says.
Meanwhile, widespread inflammation and extreme fatigue are common side effects of treatments. Some chemotherapy drugs can also weaken the heart and limit its function, according to Patel.
“Loss of endurance and overall deconditioning is a big concern,” explains Ashley Adamczyk, a physical therapist who specializes in oncological rehabilitation at Rush University Medical Center in Chicago. When people with breast cancer feel tired and weak, exercise is often the last thing they want to do – but keeping moving is exactly what’s needed to “stop the spiral” of declining cardiopulmonary and metabolic health with breast cancer treatments, she says. In fact, of the most commonly recommended treatments for cancer-related fatigue, exercise is the most effective, according to a 2017 JAMA Oncology meta-analysis of 113 prior studies.
“When doctors tell people they have breast cancer, their next words should be to start exercising,” Waltke says. “But it’s also never too late to start.”
How to Exercise When Battling Breast Cancer
When exercising during and immediately following cancer-related treatments, the most important guidelines are to keep an open dialogue with your oncological team and to listen to your body.
“People should work with their team of providers to determine the right time to start exercising,” Patel says. “The type and extent of exercise is dependent on the phase of treatment, preexisting comorbidities and the stage of cancer.”
For example, in the first several weeks following lumpectomies and mastectomies, most physicians discourage pushing, pulling, raising the arms above shoulder height or lifting or carrying heavy weights, Adamczyk explains. Some people may also have drainage tubes and bags that limit certain movements. Also, in cases of advanced cancer, tumors can metastasize to surrounding bones, increase the risk of fracture and contraindicate certain forms of exercise that could overstress the bones, she says. Talk to your doctor to make sure you have exercise clearance before doing anything more intense than walking or involving your upper body.
Also, while any physical activity is better than none, Adamczyk recommends that people with breast cancer should complete at least 150 minutes of moderate aerobic exercise each week along with two to three strength-training workouts per week.
“Moderate is relative,” Waltke says. “Do what feels moderate for you on that particular day, because things will change from day to day. Every few minutes during exercise, check in with yourself about how you feel. Do the same thing six hours later, and then again the next day. Do you feel better, the same or worse?” The answers will help guide what forms of exercise, levels of intensity and workout durations are ideal for you.
In addition to aerobic and resistance exercise, Waltke recommends performing gentle stretching and mobility exercises on a daily basis – for at least a year and a half following treatment. “It takes a good 12 to 18 months for the scar tissue and other tissue changes to happen and fully mature,” she explains.
And no matter where you are in your breast cancer recovery, don’t hesitate to reach out for support. “Long-term pain after breast surgery is not typical,” she says. “If someone is having pain, limited mobility or weakness even months or years after breast cancer surgery, it’s not too late to do something about it.”