It is widely known—and repeatedly proven—that exercise goes a long way toward preventing and treating chronic diseases such as obesity, diabetes, and cardiovascular disease. Less frequently studied are the effects of exercise on cancer—from prevention to survivorship—though this is now recently changing.

A Correlation between Exercise and Survivorship

Among breast cancer survivors, physical activity after diagnosis has consistently been associated with a reduced risk of breast cancer recurrence and breast cancer-specific mortality. A recent meta-analysis showed that exercise post-diagnosis was associated with a 34 percent lower risk of breast cancer deaths, a 41 percent lower risk of all-cause mortality, and a 24 percent lower risk of breast cancer recurrence.[1]

Researchers such as Lee Jones, PhD, and his team in the Cardio-Oncology Research Program at Memorial Sloan Kettering Cancer Center are investigating how exercise may mitigate some side effects of treatment as well as prevent cancer and its recurrence. This breaking research also includes the potential effect of exercise on metastatic (or spreading) disease. Dr. Jones stated, "I believe exercise may be able to actually change the microenvironment of such tissues to keep metastatic cancer cells asleep for longer—and perhaps even permanently."[2]
 

How Exercise Combats Cancer

The American Cancer Society (ACS) recommends "multi-modal training:" a combination of cardio, strength, and flexibility exercises. Each mode is important because they each work to counteract a specific, detrimental effect of cancer:

• Chemotherapy, according to Dr. Jones, can have the same wear-and-tear effect on the  cardiovascular system  as ten years of normal aging.[3]  Aerobic activity such as running, cycling, swimming, dancing, and cross-country skiing are important to help counteract these detrimental effects to the heart and cardiovascular system.
• Cancer (along with other illnesses) also speed up natural aging's effect on our  lean body mass  (LBM) or muscle tissue, which tends to decrease with age. Cancer accelerates LBM loss, particularly due to changes in nutritional status due to decreased intake and/or impaired nutrient absorption. Strength training helps to maintain and build LBM.
• Cancer can increase susceptibility to injury due to decreased stamina. Flexibility training helps improve posture, prevent injuries, and promote a full range of motion.

In a study among 3,000 breast cancer survivors, higher levels of post-treatment exercise correlated with a 26 to 40 percent reduced risk of recurrence and mortality (from cancer or otherwise). These benefits were achieved with 1-3 hours of exercise per week and a further reduction of risk in those who worked out 3-5 hours per week. Similar associations are demonstrated in colorectal, prostate, and ovarian cancer survivors.

Measuring Intensity with the Talk Test

Your doctor might advise you to take only light or moderately intense exercise during a particular phase of your treatment or recovery.

Here's a little cheat sheet to know what that means:

Light intensity: You are able to sing while exercising.

Moderate intensity: You can comfortably converse, if not exactly belt out your favorite jam.

Vigorous: You manage to say a few words—"When is this hill over??"—before pausing for a breath.[4]
 

Proceed with Caution

Like anyone with a serious health condition, cancer patients and survivors should be particularly sensitive listening to their bodies (and their medical practitioners) before starting any new exercise program, particularly in light of the possibility of cancer-related fatigue syndrome.

Cancer—or its treatments—can leave patients unduly fatigued. Such chronic tiredness affects 75-95 percent of all cancer patients and survivors, manifesting in both physical and/or psychological factors. Physical factors include altered digestion (impaired nutrient absorption), decreased strength, cardiovascular changes, and vascular abnormality (decrease in blood cells and platelets). Psychological factors could include sleep disturbances and depression.

Research shows a correlation between increased exercise and decreased levels of fatigue in survivorship. In another meta-analysis of 44 studies that included over 3,000 participants with varying cancer types, cancer survivors randomized to an exercise intervention had significantly reduced cancer-related fatigue levels, with evidence of a linear relationship to the intensity of resistance exercise. In many studies, exercise shows a beneficial effect on fatigue, cardiovascular fitness, muscle strength, body composition, joint pain, anxiety, depression, self-esteem, happiness, and quality of life.

The goal is to find a balance that leads to a lifetime commitment and soulful engagement to exercising. Listen to your body (check out the side bar to the right), try not to have expectations, and ask yourself: what can I do  today?

The Pilates Prescription

Memorial Sloan advocates Pilates as an excellent method of exercise for cancer survivors. They value Pilates for the way it promotes musculo-skeletal balance, mindful breathing, and spinal alignment, which leads to increased strength support, pain relief, and improved function. Pilates minimizes unnecessary muscle recruitment, prevents early fatigue, increases stability, fosters recovery of— and prevents further—injury, heightens body awareness, improves balance, coordination, circulation, endurance, and strength, provides stability of spine and pelvis, and overall improves functional postures and movements. And if all that wasn't enough, Pilates may assist with improving arthritis, hypertension, and degenerative disorders, all while helping to decrease anxiety, blood pressure, pain, and stiffness.

Sounds amazing, right? But again, we have to emphasize the importance of talking with your doctor before beginning any new exercise program, since there are some contraindications to exercise with cancer. Stop immediately if you experience chest pain, shortness of breath, nausea, vomiting, fever, serious pain, nose bleed or more.[5]  Pretty good words of advice for anyone, cancer survivor or not.

If you are a cancer survivor or if you have a loved one who has battled with cancer and incorporated exercise into his or her recovery or survivorship, tell us about it! What type of exercise was most beneficial—or dreaded—and why?