#099 The Science of Exercise for Cancer | Kerry Courneya, PhD

Mar 3, 2025 Episode Page ↗
Overview

Dr. Kerry Courneya, a leading expert in exercise oncology, discusses how exercise has shifted from an optional to a therapeutic intervention for cancer. He explains its role in prevention, enhancing treatment tolerance, improving survival outcomes, and mitigating side effects across various cancer types.

At a Glance
32 Insights
1h 51m Duration
19 Topics
8 Concepts

Deep Dive Analysis

Introduction: Exercise as a Therapeutic Cancer Intervention

Cancer Prevention: Lifestyle Shifts and Risk Reduction

Exercise Intensity and Dose-Response for Cancer Prevention

Pre-Diagnosis Exercise Benefits and Cancer Preparedness

Muscle Mass, Sarcopenia, and Cancer Outcomes

Structured Exercise vs. Daily Activity for Cancer Prevention

Cancer Treatment Landscape and Exercise Integration

Exercise for Managing Treatment Side Effects and Tolerance

Mechanisms of Exercise Affecting Primary Tumors

Exercise and Circulating Tumor Cells: Preventing Metastasis

Cancer Metastasis Timelines and Liquid Biopsies

Exercise-Sensitive vs. Exercise-Resistant Cancers

Weight Training for Prostate Cancer on Androgen Deprivation Therapy

Exercise as Monotherapy for Low-Grade Cancers (Active Surveillance)

Psychological Benefits of Exercise in Cancer Patients

Exercise Across the Cancer Care Continuum

Challenges and Support for Exercise Adherence in Cancer Patients

Cost-Effectiveness of Exercise in Cancer Care

Myths and Nuances of Exercise in Cancer

Prehabilitation

This concept involves preparing the body through fitness for the eventuality of chronic disease diagnosis and its treatments. It aims to reduce complications, shorten hospital stays, and improve recovery after medical interventions.

Cachexia

Cachexia is a severe wasting disease phenomenon observed in cancer patients, particularly those with advanced or metastatic cancer, characterized by significant muscle wasting. Low muscle mass in this state is a critical factor driving the risk of recurrence and death from cancer.

Sarcopenic Obesity

This condition describes individuals who have high rates of obesity but also low lean body mass. It highlights that Body Mass Index (BMI) alone is not a sufficient measure of body composition, as the ratio of fat mass to lean mass is a more important factor for health outcomes.

Neoadjuvant Therapy

Neoadjuvant therapy refers to cancer treatments, such as chemotherapy or radiation, administered before the main treatment like surgery. The goal is to shrink or eliminate the tumor prior to surgical removal, and exercise can potentially enhance its effectiveness.

Circulating Tumor Cells (CTCs)

These are cancer cells shed from a primary tumor that travel through the bloodstream, capable of spreading cancer to other parts of the body. Exercise may reduce the survival of these cells due to increased shear stress from blood flow.

Liquid Biopsies

Liquid biopsies are experimental blood tests designed to detect small numbers of circulating tumor cells or circulating tumor DNA. This technology aims to allow for earlier detection of cancer or recurrence than traditional imaging, potentially revolutionizing cancer care.

Active Surveillance

Active surveillance is a cancer management approach for small, low-grade, slow-growing cancers, primarily used in prostate cancer, where initial treatment is withheld. Instead, the cancer is closely monitored, allowing for lifestyle interventions like exercise to potentially delay or prevent the need for more aggressive treatments.

Fear of Cancer Progression/Recurrence

This is a significant psychological issue for cancer patients who, even after successful treatment, live with the anxiety and stress of potential cancer return. This fear can be paralyzing and is often exacerbated by regular follow-up screenings that determine if the cancer has come back.

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What is the single best lifestyle shift for cancer prevention (assuming no smoking)?

Assuming you're not smoking, obesity is the second biggest risk factor, followed by alcohol consumption. If none of these apply, exercise is next on the list, with general recommendations of 150 minutes per week of moderate to vigorous aerobic exercise.

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Does exercise reduce cancer risk even for obese individuals or smokers?

Yes, exercise lowers the risk of cancer regardless of obesity status, and even for smokers, though quitting smoking has a larger impact on risk reduction.

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Is "weekend warrior" exercise effective for cancer prevention?

Yes, current exercise guidelines for cancer prevention do not specify how exercise must be spread out over the week. Accumulating 150 minutes per week over a weekend can be as beneficial as distributing it throughout the week.

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Is daily activity or house chores enough to reduce cancer risk, or is structured exercise necessary?

The recommended 150 minutes per week of moderate intensity exercise is above and beyond background activity; daily movement is important but not a replacement for a structured exercise program.

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How does exercise help cancer patients tolerate chemotherapy and radiation?

Exercise helps patients complete more of their chemotherapy treatments with fewer reductions or delays. It also improves the delivery of drugs to tumors and makes tumors more radiosensitive by enhancing blood flow and oxygenation.

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Why is muscle mass critical for cancer patients?

Low muscle mass is a critical factor driving the risk of recurrence and death from cancer, as cancer can cause muscle wasting (cachexia). Having muscle reserves helps patients endure the disease and its treatments.

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How does exercise directly affect primary tumors during treatment?

Exercise improves the quality and density of blood vessels within primary tumors, enhancing chemotherapy drug delivery and making tumors better oxygenated and thus more sensitive to radiation therapy.

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How does exercise prevent cancer metastasis?

Exercise increases blood flow and shear stress in the vasculature, which makes circulating tumor cells less likely to survive their journey and spread to other organs.

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How long does cancer metastasis typically take, and does it vary by tumor type?

Metastasis varies dramatically by cancer type; sometimes small tumors shed cells that spread quickly, while other times disseminated cells can sit dormant for years before regrowing.

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Can exercise act as a monotherapy for certain low-grade cancers?

Yes, studies in prostate cancer patients on active surveillance have shown that high-intensity exercise can lower prostate-specific antigen (PSA) levels and reduce the growth of prostate cancer cells in vitro.

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What are the psychological benefits of exercise for cancer patients?

Exercise helps cancer patients feel more in control and normal, improving self-confidence, self-esteem, and managing anxiety, depression, and fear of cancer progression or recurrence.

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What percentage of cancer patients meet exercise guidelines during treatment?

During treatments, no more than 5% to 10% of cancer patients meet exercise guidelines, though this increases to 30% to 40% in the survivorship phase after treatment.

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How can sedentary cancer patients be motivated and supported to exercise?

Motivation comes from understanding cancer-specific benefits, starting with realistic and feasible programs, and receiving strong recommendations and support from oncologists and the cancer care team.

1. Quit Smoking for Cancer Prevention

Quit smoking immediately as it is the biggest risk factor for cancer, and doing so can substantially reduce your risk with fairly quick benefits.

2. Manage Obesity for Prevention

If you are obese, engage in a weight loss program to reduce obesity, as it is the second leading risk factor for developing cancer after smoking.

3. Reduce Heavy Alcohol Consumption

Lower your alcohol intake if you are a heavy drinker, as there is a significant link between alcohol consumption and various alcohol-related cancers.

4. Engage in Lifelong Exercise

Exercise throughout your lifetime to prepare your body for potential chronic diseases and their treatments, acting as ‘pre-habilitation’ for future health challenges.

5. Build Muscle Reserve

Incorporate regular resistance training to build and maintain muscle mass, which is critical for cancer patients and helps combat muscle wasting (cachexia) during illness.

6. Prioritize Structured Exercise

Engage in a good quality structured exercise program combining aerobic and strength training, as this is essential and not replaced by general daily background activity.

7. Aim for 150-300 Minutes/Week

Target 150 to 300 minutes per week of moderate to vigorous intensity aerobic exercise for optimal cancer prevention benefits, with 150 minutes as the minimum.

8. Increase Exercise for Family History

If you have a family history of cancer, aim for the higher end of exercise recommendations (e.g., 300 minutes/week) to maximize benefits and risk reduction.

9. Exercise Regardless of Risk Factors

Exercise to lower your cancer risk even if you are obese, have a family history, or have smoked, as its benefits extend to high-risk populations.

10. Exercise to Reduce Fatigue

Actively exercise during chemotherapy to experience lower fatigue, as resting can paradoxically lead to more reported fatigue in cancer patients.

11. Exercise Improves Treatment Completion

Exercise during chemotherapy to improve your ability to complete treatments, leading to fewer drug reductions or delays, a higher chance of cure, and lower recurrence risk.

12. Enhance Treatment Effectiveness

Exercise to improve blood flow and oxygenation to tumors, which enhances the delivery of chemotherapy drugs and makes tumors more sensitive to radiation therapy.

13. Reduce Cancer Metastasis

Exercise to increase blood flow and shear stress in the vasculature, which helps kill circulating tumor cells and reduces the likelihood of cancer spreading.

14. Boost Immune System with Exercise

Stimulate your immune system through exercise to increase natural killer cells, T cells, and B cells, enhancing immunosurveillance against cancer cells.

15. Lower Recurrence and Mortality

Continue exercising post-treatment to lower the risk of cancer recurrence and dying from cancer, as shown by a growing body of epidemiological research.

16. Prevent Secondary Chronic Diseases

Exercise after cancer treatment to reduce the risk of secondary chronic diseases like cardiovascular disease, osteoporosis, and diabetes, which can be increased by cancer therapies.

17. Manage Fear of Recurrence

Use exercise to manage the fear of cancer progression or recurrence, helping patients cope with psychological stress and feel more in control of their lives.

18. Exercise: A ‘Win-Win’ Intervention

Prioritize exercise as a unique intervention that simultaneously improves quality of life, manages side effects, and enhances disease-free survival in cancer patients.

19. 15-Minute Strength Training

If you only have 15 minutes a day, prioritize heavier, compound strength training (e.g., squats) to target muscle mass, which is critical for treatment, survival, and quality of life.

20. Weight Training During Treatment

Follow a full-body weight training program 2-3 days per week (e.g., 8 exercises, 8-12 reps to failure) during cancer treatment, as it’s been shown to be very beneficial.

21. Combine Aerobic & Resistance

Combine aerobic and resistance exercise during treatment for additional benefits in muscular strength, lean body mass, and symptom management.

22. Consider Higher Intensity Exercise

Explore higher intensity exercise, such as high-intensity interval training (HIIT), as it appears to be more beneficial for driving biological changes relevant to cancer treatment.

23. HIIT for Prostate Cancer

For men with prostate cancer on active surveillance, use high-intensity interval training (HIIT) to lower PSA levels and reduce the growth of prostate cancer cells.

24. Individualize Exercise Programs

Ensure exercise programs are individualized and progress slowly for cancer patients, especially those new to exercise, to ensure safety, tolerability, and adherence.

25. Get Oncologist’s Recommendation

Seek your oncologist’s recommendation for exercise, as their endorsement is crucial for motivating patients to incorporate physical activity into their cancer care.

26. ASCO Recommends Exercise

Be aware that the American Society of Clinical Oncology (ASCO) recommends aerobic and resistance exercise for all cancer patients undergoing curative intent treatments.

27. Seek Exercise Support

Actively seek support and intervention to maintain exercise during cancer treatment, as the natural tendency is to reduce activity levels without assistance.

28. Utilize Community Programs

Access community-based exercise programs like Livestrong at the YMCA or specialized programs at cancer centers, which offer expert support for cancer survivors.

29. Start with Walking Program

If you’re new to exercise or facing tough treatment phases, start with a walking program, as it’s a realistic, feasible, and beneficial way to begin.

30. Break Sedentary Time

Break up extended periods of sitting by getting up and moving around, as sedentary time is an independent risk factor for various cancers.

31. Short Bursts of Vigorous Activity

Accumulate short bursts of vigorous intensity activity (e.g., 1-2 minutes) throughout the day, as these can have beneficial effects even if not part of a continuous workout.

32. Sun Protection During Exercise

Wear sunscreen and protective clothing during outdoor exercise to prevent skin cancer, as regular exercisers have higher rates due to increased sun exposure.

Exercise is not just supportive, it's a therapeutic intervention that recalibrates tumor biology, it enhances treatment tolerance, and it improves survival outcomes.

Dr. Rhonda Patrick

Assuming you're not smoking, which is 80 to 85% of the American population, obesity is actually the second on the list of risk factors for developing cancer.

Dr. Kerry Courneya

The patients that rested during chemotherapy actually reported more fatigue than the patients who exercise.

Dr. Kerry Courneya

Exercise, in some ways, was the original immunotherapy.

Dr. Kerry Courneya

Don't take cancer lying down.

Dr. Kerry Courneya

Exercise is one of these few interventions potentially for patients that can help both with quality of life, side effect symptoms, and also improve disease-free survival.

Dr. Kerry Courneya

If we can demonstrate in a larger study that exercise lowers the risk of recurrence, he said that would change the game. He says, you know what it costs when a breast cancer patient has a recurrence? A million dollars.

Dr. Kerry Courneya

Standard Full-Body Weight Training Program (for cancer patients)

Dr. Kerry Courneya
  1. Perform weight training 3 days per week.
  2. Include approximately 8 exercises covering all major muscle groups.
  3. Train at a moderate intensity, aiming for 8 to 12 repetitions before failure for each exercise.
2 million
Annual cancer diagnoses in the U.S. Estimated number of Americans diagnosed with cancer each year.
40%
Percentage of cancers preventable by optimal lifestyle changes Estimated by the American Cancer Society.
80% to 85%
Percentage of American population not smoking Current estimate of non-smokers in the U.S.
8 to 10
Number of cancer types with reduced risk from exercise Different cancer types whose risk is lowered by regular physical activity.
150 minutes per week
General public health guideline for moderate-to-vigorous aerobic exercise Minimum recommended for cancer prevention and general health benefits.
Up to 300 minutes per week
Optimal guideline for moderate-to-vigorous aerobic exercise for cancer prevention Benefits continue to accrue up to this amount, then plateau.
75 minutes per week
Vigorous intensity exercise equivalence Equivalent to 150 minutes of moderate intensity exercise (double credit).
Over 1 kilogram
Muscle mass gained by weight training group during chemotherapy Observed in a study of cancer patients undergoing chemotherapy.
1 mm, 2 mm
Tumor size for detection on scans Minimum size for metastases to show up on traditional imaging scans.
80%
Sensitivity of new colon cancer blood test Compared to colonoscopy, for detecting colon cancer.
90%
Specificity of new colon cancer blood test Compared to colonoscopy, for detecting colon cancer.
5% to 10%
Percentage of cancer patients meeting exercise guidelines during treatment Observed in surveys of cancer patients.
30% to 40%
Percentage of cancer patients meeting exercise guidelines after treatment (survivorship) Observed in surveys, an increase from during-treatment levels but not back to pre-diagnosis.
$1 million
Estimated cost of a breast cancer recurrence to the healthcare system Estimate for all drugs, treatments, and medical care required.
10%
Percentage of preclinical animal studies showing exercise exacerbates tumor growth The majority (90%) show exercise slows tumor growth and spread, but a small percentage show the opposite effect without a clear pattern.