By Karen M. Basen-Engquist, Ph.D., M.P.H., professor, Department of Behavioral Science, MD Anderson Cancer Center
Evidence is accruing that exercise can help cancer survivors feel better and improves their health.
In the past, cancer survivors were often told that they should rest. While rest is important, getting off the couch and moving also provides benefits.
A number of studies have been conducted over the past 12 years showing that exercise improves fitness in cancer survivors, enhances quality of life and reduces side effects such as fatigue and anxiety.
Additionally, many cancer survivors have declines in physical functioning. They are not able to participate in the same activities or do their daily tasks as effectively as before their diagnosis.
Exercise has been shown to improve physical functioning, helping survivors get back to their usual activities. Patients undergoing treatment, as well as survivors who have completed their treatment, experience benefits.
Exercise is associated with many additional health benefits, including reducing the chances of hypertension, heart disease, stroke and diabetes, and improving physical functioning of individuals with arthritis and other musculoskeletal conditions.
Cancer survivors can be at increased risk of these chronic diseases, because the diseases share risk factors with cancer or because cancer treatment has left survivors more vulnerable to their effects. Does exercise affect cancer prognosis?
This question is often foremost in the minds of cancer survivors. Research provides us with some good news. Epidemiologic studies have shown that exercising individuals are less likely to develop certain cancers like colon
, post-menopausal breast
and endometrial cancer.
This has led to speculation that exercise might affect prognosis for people who have been diagnosed with cancer. Several cohort studies have indicated that doing more leisure-time physical activity after cancer diagnosis is associated with a reduced risk of recurrence and cancer death for breast cancer and colon cancer survivors.
A fairly modest amount of exercise improved outcomes. Risk of recurrence was lowered with as little as three hours per week of brisk walking for breast cancer and six hours for colon cancer. However, we do not have evidence from randomized controlled trials that exercising after a cancer diagnosis improves prognosis. Exercise guidelines for cancer survivors
The benefits that exercise offers have led the American College of Sports Medicine
to develop cancer survivor exercise guidelines. They convened a panel of experts to review the literature and make recommendations. The panel's recommendation was clear: avoid inactivity
, both during and after treatment (K Schmitz, et al, Medicine & Science in Sports & Exercise, 2010).
With a few exceptions, they recommend that cancer survivors follow the age-appropriate recommendations for the general population -- 150 minutes of moderate intensity or 75 minutes of vigorous intensity aerobic activity per week, and resistance training of all major muscle groups two days per week.
They point out that certain groups of survivors, such as those with metastatic disease, known cardiac problems or other health problems, should consult with a physician before exercise.
For aerobic exercise, most cancer survivors can follow the general population recommendations. However, those with an increased risk of falling or bone fractures (for example, survivors with peripheral neuropathy
or bone metastases) should consider non-weight bearing activity, such as riding a stationary bicycle.
Resistance exercise is an important part of the fitness routine, and can be done safely by cancer survivors. Those at risk for lymphedema or who have stomas should take care to start with a low resistance level and progress slowly. A supervised program is recommended for these survivors.
While special considerations are needed regarding exercise for certain groups of survivors, the message in these recommendations is clear -- survivors should keep MOVING
Basen-Engquist spoke about exercise and cancer at a major forum this week at the American Association for Cancer Research 102nd Annual Meeting.