Returning to Exercise & Movement After Cancer Treatment

The number usually quoted after cancer treatment is around 150 minutes of moderate aerobic activity a week. Add resistance training on two days. Cover the major muscle groups. That matches the general physical activity guidelines. It is a reasonable destination.

It is not where you have to begin. The American College of Sports Medicine held a roundtable on exercise and cancer. The doses that clearly helped were smaller. They came to roughly 30 minutes of moderate aerobic activity three times a week. That is about 90 minutes in total, kept up for around 12 weeks. At that dose, trials showed better fatigue, anxiety, mood and quality of life. Resistance work gave similar gains. The usual dose was two sets of 8 to 15 repetitions, two to three times weekly. Doing both worked best of all for quality of life.

So think of it this way. 150 minutes is a destination. 90 minutes is already a therapeutic dose. And if ten minutes is where you are, ten minutes is where you start.

Fatigue. This is the one that surprises people. Cancer-related fatigue responds to exercise better than to rest. One detail is critical. ACSM found that light activity is unlikely to reduce fatigue. The effect needs moderate intensity, about 65 percent of maximum heart rate. That is the level where you can talk but not sing.

Mood and quality of life. Moderate aerobic training three times a week improved anxiety and low mood across trials. Supervised programs generally beat unsupervised ones.

Physical function. Strength, walking capacity, and balance all improve. It takes combined aerobic and resistance work over 8 to 12 weeks.

Possibly outcomes. Observational studies have long tied activity to lower recurrence and mortality in breast and colorectal cancer. But that kind of data has a flaw. It cannot separate exercise from simply being well enough to exercise. The CHALLENGE trial changed that. It randomised 889 people who had finished adjuvant chemotherapy for colon cancer. Half got a three-year structured exercise program with a coach. Half got health education materials. Five-year disease-free survival was 80 percent with the program, against 74 percent without. Eight-year overall survival was 90 percent against 83 percent. Musculoskeletal adverse events were a bit more common in the exercise arm. So this is randomised proof that structured exercise changes outcomes, at least in this setting.

Bone metastases. Get clearance first. Then avoid high-impact loading. Avoid dynamic twisting of the trunk. Avoid trunk hyperflexion and hyperextension, and loaded flexion and extension. Machine-based or supported resistance work is usually better. New or changing bone pain means stopping and contacting your team.

Peripheral neuropathy. Have your stability, balance, and gait checked before you start. Stationary cycling or water-based exercise often stands in well for walking. A treadmill with side rails is another option. Is your grip sensation reduced? Then machines or padded dumbbells can be easier than free weights. Balance training is worth including.

Lymphoedema, or risk of it. Slowly progressive resistance training is safe for breast cancer survivors. It is recommended. Three conditions come attached. Start under supervision. Start light. Build up slowly. Aerobic exercise has not been shown to increase lymphoedema events. Evidence on wearing a compression garment during exercise is thin either way. Comfort and preference can guide that one.

Ostomy. Empty the pouch beforehand. Begin resistance work at low load and build slowly. Avoid the Valsalva maneuver, which means holding your breath and bearing down. Change any core exercise that makes the area around the stoma bulge. With an ileostomy, ask about hydration. A stoma protector is sensible for contact sport.

Neutropenia and immune recovery. Home-based exercise is generally encouraged. Hold off on the gym until your counts recover. Short, frequent, lighter sessions work better than long ones. You can adjust the volume day to day.

ACSM grades its advice on clearance in three steps:

• No clearance needed if you have no relevant comorbidities.
• A pre-exercise check for neuropathy, poor bone health, lymphoedema, or arthritis.
• Clearance before you begin for bone metastases, cardiopulmonary disease, extreme fatigue, ataxia, severe nutritional deficiency, or an ostomy. The same holds after recent abdominal or thoracic surgery.

Ask about a referral to a physiotherapist or cancer exercise specialist. Supervised programs consistently beat going it alone. That is most true at the start.

Stop and contact your team for chest pain, unusual breathlessness, dizziness or fainting, new or worsening bone pain, or sudden swelling in a limb. Short of that, the guiding principle from the evidence is to avoid inactivity — the benefits generally outweigh the risks.

• ACSM International Multidisciplinary Roundtable: Exercise Guidelines for Cancer Survivors (MSSE, 2019)
• ASCO: Structured exercise programme results from the CHALLENGE trial
• NCI: Physical activity and cancer
• Moving Through Cancer: making exercise standard in oncology practice