Exercise and Cancer: Understanding The Benefits
For years, exercise was seen mostly as a way to stay fit or lose weight. But over the past two decades, research has shown something far more powerful: exercise is medicine for cancer. It doesn’t just improve quality of life — it can lower your risk of developing cancer, ease side effects during treatment, and even reduce the chance of recurrence afterward.
In this article, we’ll explore the science of how exercise works against cancer, the benefits for different types of patients, precautions to consider, and practical tips for integrating exercise safely into cancer care.
Why Exercise Helps: The Mechanisms Behind the Benefits
Scientists have uncovered several ways physical activity helps the body fight cancer. These aren’t just “nice-to-haves” — they’re biological processes that directly affect cancer cells and the body’s resilience.
Hormonal Balance: Exercise reduces levels of insulin and estrogen, both of which can fuel tumor growth. This is particularly important in breast and colorectal cancers.
Lower Inflammation: Chronic inflammation creates a fertile environment for cancer. Regular movement decreases inflammatory markers in the blood.
Immune Activation: When you exercise, natural killer cells and T-cells become more active, helping your immune system detect and destroy abnormal cells.
Better Blood Flow and Oxygen Delivery: Cancer thrives in low-oxygen environments. Exercise improves circulation and oxygenation, making it harder for tumors to grow and enhancing the effectiveness of treatments like chemotherapy and radiation.
Improved DNA Repair & Antioxidant Defenses: Exercise boosts the body’s ability to repair damaged DNA and counteract oxidative stress, lowering mutation risk.
Healthier Body Composition: Maintaining lean muscle and reducing excess fat lowers metabolic risk factors linked to several cancers.
In short: exercise creates a biological environment that makes it harder for cancer to start, grow, or return.
Exercise Across the Cancer Journey
1. Before Diagnosis: Reducing Cancer Risk
Large population studies consistently show that active individuals have a 20–40% lower risk of developing cancers like breast, colon, endometrial, bladder, and esophageal cancer. Even moderate exercise — such as brisk walking 30 minutes a day — offers significant protection.
2. During Treatment: Managing Side Effects
Cancer treatments save lives, but they can also take a heavy toll. Exercise is one of the most effective tools for managing these side effects:
Fatigue: The #1 complaint during treatment. Counterintuitively, gentle activity reduces fatigue better than rest.
Cardiotoxicity: Some chemotherapy drugs damage the heart. Aerobic and resistance exercise strengthen cardiovascular health and reduce complications.
Peripheral Neuropathy: Nerve damage from chemo can cause numbness and balance problems. Targeted exercise improves stability and lowers fall risk.
Mental Health: Exercise reduces anxiety, lifts mood, and improves sleep — key factors during long treatment cycles.
3. After Treatment: Recovery and Recurrence Prevention
Survivorship doesn’t mean the journey is over. Exercise helps rebuild strength and reduces the risk of cancer returning.
Colon cancer survivors who exercise regularly see a 37% lower mortality rate.
Breast cancer survivors who are active have a 30–40% lower recurrence risk.
Survivors across cancer types report more energy, better independence, and improved quality of life.
Exercise Benefits by Cancer Type
While the overall benefits are clear, research highlights some unique advantages for different cancers:
Breast Cancer: Exercise lowers estrogen, reduces recurrence, and improves bone health. Yoga, resistance training, and aerobic exercise help with fatigue, joint pain, and lymphedema.
Colorectal Cancer: Reduces insulin resistance and inflammation. Walking and strength training are particularly protective.
Prostate Cancer: Exercise offsets muscle loss from hormone therapy, reduces cardiovascular risks, and supports healthy testosterone metabolism.
Lung Cancer: Pulmonary rehabilitation and light aerobic exercise improve breathing, endurance, and recovery from surgery.
Hematologic Cancers (e.g., leukemia, lymphoma, myeloma): Exercise supports immune recovery during and after bone marrow transplants, but must be carefully supervised due to infection and bleeding risks.
Exercise Contraindications and Precautions
While exercise is safe for most cancer patients, there are situations where modifications or medical clearance are essential:
Bone Cancer or Bone Metastases
❌ Avoid high-impact activities like running, jumping, or heavy lifting due to fracture risk.
✅ Safer alternatives: swimming, cycling, resistance bands, walking.
Compromised Immune System
❌ Avoid crowded gyms or swimming pools, especially during chemotherapy or transplant recovery.
✅ Home-based or private exercise is safer.
Peripheral Neuropathy
❌ Activities requiring high balance (e.g., trail running) increase fall risk.
✅ Stationary cycling, seated resistance, and supported balance training are better options.
Anemia or Low Platelet Counts
❌ Strenuous activity may worsen fatigue or bleeding risks.
✅ Focus on light stretching, yoga, or gentle walking until cleared.
Cardiotoxic Treatments (anthracyclines, trastuzumab, chest radiation)
❌ High-intensity unsupervised exercise may increase strain.
✅ Monitor heart rate closely and work with an exercise physiologist.
Medications and Exercise: Timing is Key
Cancer treatments can affect energy levels, hydration, and safety during exercise. Here’s what to know:
Chemotherapy: Fatigue typically peaks 1–2 days after infusion. Plan exercise on “better” days, at lower intensity.
Steroids: Can cause high blood sugar, high blood pressure, or muscle weakness. Exercise earlier in the day when energy is higher.
Hormonal Therapies (e.g., tamoxifen, aromatase inhibitors): Exercise helps counteract joint stiffness, bone density loss, and weight gain.
Pain or Anti-nausea Medications: Be mindful of dizziness or sedation — choose low-risk, stable exercises when medicated.
Special Tips for Exercising with Cancer
Always get medical clearance, especially with bone involvement, anemia, or heart risks.
Start low and go slow: Begin with 10–15 minutes of activity and progress gradually.
Mix modalities: Aerobic, resistance, flexibility, and mind-body practices like yoga offer different benefits.
Stay hydrated and nourished: Cancer treatments increase fluid and nutrient needs.
Seek expert support: An exercise physiologist or physiotherapist trained in oncology can tailor a safe, effective plan.
Conclusion
Exercise is not just “allowed” during cancer — it’s one of the most powerful tools patients and survivors can use to improve outcomes. From reducing the risk of diagnosis to managing side effects during treatment and preventing recurrence afterward, movement is truly medicine.
With the right guidance and precautions, exercise can help people with cancer feel stronger, recover faster, and reclaim control over their health. If you have questions about starting an exercise program contact us. We’re here to help you achieve your health and fitness goals.
The information in the blog is provided for informational and educational purposes only and does not constitute medical advice. The information is not a substitute for professional medical advice, diagnosis, or treatment. For questions please follow up with your healthcare professional.
