For a long time, conventional wisdom maintained that people with cancer should not exercise, under the prevailing belief that it would worsen the patient’s condition and deplete their already limited energy reserves. However, this perspective has completely shifted in recent years. There are now over 1,000 randomized controlled trials that unequivocally support the idea that exercise is not only safe but immensely beneficial for everyone, including those battling cancer!
Exercise is such a formidable ally in the battle against cancer, it really should be prescribed right along with non-toxic treatments, adequate sleep, and a diet rich in fruits and vegetables. That is because exercise has shown time and time again to elicit measurable improvements in survival and prognosis! Even beyond these significant benefits, regular exercise has been shown to profoundly enhance the quality of life and mental health of cancer patients, providing a much-needed boost during challenging times. Furthermore, engaging in physical activity has been shown to not only complement the effectiveness of cancer treatments but also to mitigate their side effects.
Before we dive into the specific ways exercise can help beat cancer, it’s crucial to recognize that engaging in exercise does not necessarily mean undertaking extreme activities such as running a marathon. Exercise encompasses a broad spectrum of physical activities, ensuring there is a suitable option for everyone, regardless of their fitness level or health status. This can be something as accessible and low-impact as walking, which provides significant health benefits without the strain of more intense exercise routines.
To determine an exercise routine that best fits your individual needs and circumstances, consulting with healthcare professionals who specialize in both oncology and physical therapy is a wise step. Examples of specialists include oncology physiotherapists and certified cancer exercise specialists; these professionals are trained to create and tailor exercise programs that safely match the cancer patient’s specific medical situation, phase of treatment, and rehabilitation needs. They can provide personalized advice and guidance, ensuring that your physical activity supports your health and healing journey effectively.
That being said, don’t wait to get started! To bridge the gap between intention and action, here are six compelling, evidence-based benefits of exercise that shed light on its pivotal role in both the prevention and treatment of cancer.
1. Exercise prevents cancer
First, it’s impossible not to mention the fact that regular physical activity dramatically decreases the risk of developing over 7 different types of cancer (1). For example, one analysis of over 126 studies showed physically active individuals had a 19% lower risk of developing colon cancer compared to sedentary individuals (2). This is reflected across the board—physically active individuals are 20% less likely to develop endometrial cancer, 19% less likely to develop stomach cancer, and 23% less likely to develop kidney cancer (3).
One reason for this is due to weight control. Since exercise promotes a healthy weight, individuals can avoid obesity and its associated cancer-promoting effects. Exercise also plays an important role in regulating hormone levels. By enhancing insulin sensitivity and regulating hormones like estrogen and progesterone, exercise reduces the risk of hormone-sensitive cancers such as breast and endometrial cancers (3). Regular movement has even been shown to decrease chronic inflammation, a widespread condition clearly linked with cancer and chronic disease (3).
If you have already been diagnosed with cancer, don’t lose hope! As you will see below, the benefits of exercise extend far beyond prevention.
2. Exercise enhances the effectiveness of cancer treatments
It’s true—research shows that exercise can make cancer treatments work better. A research study showed that when mice with pancreatic cancer exercised while receiving chemotherapy, their cancer growth slowed down significantly compared to those who didn’t exercise (3). The same phenomenon is seen in humans, too. One clinical trial of patients with colon cancer found that those who exercised more after receiving chemotherapy had a better chance of staying cancer-free for the next three years compared to those who exercised less (3).
There are several explanations for this. One is because exercise improves blood flow, which in turn increases the delivery of oxygen, immune cells, and therapeutic agents to the tumor site! (4) It also induces physiological changes and normalizes the chaotic and disorganized blood vessels around tumors, which also increases blood flow to the tumor. Additionally, physical activity appears to amplify the body’s natural defenses against cancer cells. For example, it increases the activity of key immune cells such as natural killer cells that are crucial in targeting tumor cells. This amplified immune function further improves the outcomes of both conventional and non-toxic cancer treatments (5).
3. Exercise improves survival and decreases cancer recurrence
Regular exercise has a profound impact on improving survival rates and reducing the likelihood of cancer recurrence (6). Studies in patients with breast, colon, and prostate cancers have shown that those who maintain an active lifestyle have significantly higher chances of survival compared to those who lead a sedentary life. By engaging in regular physical activity, these individuals effectively lower their risk of dying from cancer by approximately 40 to 50%—that’s like cutting their risk in half, just by being physically active! (7)
This incredible reduction in risk is largely due to exercise’s ability to change how cells work. Earlier, we discussed how exercise modulates the immune system, which is one factor at play here. But other factors include how exercise impacts the metabolism of cancer cells by slowing down their growth and spread. Additionally, exercise helps to trigger a process in the body that makes cancer cells self-destruct, a phenomenon known as apoptosis. This is because physical activity improves the body’s internal environment, making it harder for cancer cells to grow and spread (3). All of these positive factors combine to increase survival and make cancer recurrence less likely!
4. Exercise reduces the side effects of cancer and conventional treatments
It’s no secret that conventional cancer treatments have a slew of toxic side effects. However, for those who choose this route, regular physical exercise can help decrease some of the negative effects. For example, studies have shown that maintaining an exercise routine while undergoing chemotherapy can reduce common side effects such as cardiac toxicity, lymphedema, bone mass reduction, and cognitive decline (3). Physical activity also seems to help with some of the gastrointestinal side effects that come with conventional cancer treatments, such as nausea, constipation, and diarrhea, since activity helps stimulate the normal contractions of the intestines.
Even aside from conventional treatments, cancer itself comes with side effects like fatigue and cachexia (cancer-related muscle loss). Regular exercise, especially exercise like strength training that focuses on building muscle, can prevent, slow down, and reverse cancer-related muscle loss (8). Similar positive effects are seen with cancer-related fatigue as well. Although it makes sense that rest would improve fatigue, the opposite has proven to be true—physical activity actually improves cancer-related fatigue! Several studies have shown that aerobic exercise in particular improves fatigue, not only boosting the mood but improving muscle strength and cardiovascular fitness, making it easier to perform daily activities without getting tired quickly (3).
5. Exercise enhances the quality of life and restores function and mobility
Exercise plays a crucial role in restoring function and mobility for cancer patients, acting as a bridge to reclaiming their physical independence and enhancing their quality of life. Through tailored exercise programs, patients can gradually rebuild muscle strength, enhance flexibility, and improve endurance, which are often compromised due to the cancer itself or the side effects of treatment. Regular physical activity not only helps in alleviating symptoms such as fatigue and muscle weakness but also contributes to better balance and coordination, reducing the risk of falls and injuries. As patients engage in exercise, they often experience significant improvements in their ability to perform daily activities, leading to a more active and autonomous lifestyle. Moreover, the psychological benefits of regaining physical function cannot be overstated, as it fosters a sense of achievement, boosts self-esteem, and promotes a positive outlook during and after cancer treatment.
6. Exercise improves mental health
There is a wealth of evidence demonstrating the profound impact of exercise on mental health. Numerous studies have consistently shown that engaging in regular physical activity can alleviate symptoms of anxiety and depression, enhance mood, and reduce stress levels (9). Moreover, exercise has been linked to improved sleep patterns, increased self-esteem, and a heightened sense of overall well-being. Long-term participation in physical activities like running, swimming, or even yoga has been associated with a reduced risk of developing mental health disorders, offering a powerful, evidence-based approach to bolstering emotional and psychological resilience.
Traditionally, the mood-lifting effects of exercise were attributed to the release of endorphins, chemicals in the brain often dubbed as “feel-good” hormones. However, it’s now understood that endorphins cannot cross the blood-brain barrier, leading scientists to reconsider the biological underpinnings of the mental health benefits associated with physical activity. Recent discoveries have spotlighted the role of ‘endocannabinoids,’ a class of naturally occurring compounds in the body that can cross into the brain and significantly impact our sense of well-being. Unlike endorphins, endocannabinoids play a crucial role in modulating mood, reducing stress, and enhancing feelings of pleasure and satisfaction (10).
When we exercise, our muscles also produce a category of proteins called myokines. These proteins communicate with the muscles and organs, playing a key role in reducing inflammation, bolstering the immune system, and enhancing metabolic health. Intriguingly, these molecules have been nicknamed “hope molecules” due to their remarkable ability to penetrate the blood-brain barrier, elevating mood and alleviating symptoms of depression (11). Some studies also point to the potential of specific myokines to directly counteract cancer cell growth, showcasing their impact on both physical and mental well-being (12).
Overall, it’s clear that physical activity is a cornerstone in the fight against cancer! From reducing the risk of developing cancer, enhancing the effectiveness of treatments, improving survival rates, and boosting mental health and quality of life, the role of exercise in healing cannot be denied. Often, the initial step is the most challenging; but once you start this journey, the improvements you experience will add momentum, making it easier to sustain your physical activity over time. Given the overwhelming support from research, there’s no reason to let fear or hesitation hold you back. By taking proactive steps towards maintaining an active lifestyle, you can significantly contribute to your health and well-being, turning the tide in the battle against cancer without delay.
References:
1. National Cancer Institute, Physical Activity and Cancer. (2020).
2. Liu, L., Y. Shi, T. Li, et al., Leisure time physical activity and cancer risk: evaluation of the WHO’s recommendation based on 126 high-quality epidemiological studies. Br J Sports Med, 2016. 50(6): p. 372-8.
3. Wang, Q. and W. Zhou, Roles and molecular mechanisms of physical exercise in cancer prevention and treatment. J Sport Health Sci, 2021. 10(2): p. 201-210.
4. Betof, A.S., C.D. Lascola, D. Weitzel, et al., Modulation of murine breast tumor vascularity, hypoxia and chemotherapeutic response by exercise. J Natl Cancer Inst, 2015. 107(5).
5. Pedersen, L., M. Idorn, G.H. Olofsson, et al., Voluntary Running Suppresses Tumor Growth through Epinephrine- and IL-6-Dependent NK Cell Mobilization and Redistribution. Cell Metab, 2016. 23(3): p. 554-62.
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7. McTiernan, A., C.M. Friedenreich, P.T. Katzmarzyk, et al., Physical Activity in Cancer Prevention and Survival: A Systematic Review. Med Sci Sports Exerc, 2019. 51(6): p. 1252-1261.
8. Hardee, J.P., B.R. Counts, and J.A. Carson, Understanding the Role of Exercise in Cancer Cachexia Therapy. Am J Lifestyle Med, 2019. 13(1): p. 46-60.
9. Guszkowska, M., Effects of exercise on anxiety, depression and mood. Psychiatr Pol, 2004. 38(4): p. 611-20.
10. Amatriain-Fernandez, S., H. Budde, T. Gronwald, et al., The Endocannabinoid System as Modulator of Exercise Benefits in Mental Health. Curr Neuropharmacol, 2021. 19(8): p. 1304-1322.
11. Mucher, P., D. Batmyagmar, T. Perkmann, et al., Basal myokine levels are associated with quality of life and depressed mood in older adults. Psychophysiology, 2021. 58(5): p. e13799.
12. Schnyder, S. and C. Handschin, Skeletal muscle as an endocrine organ: PGC-1alpha, myokines and exercise. Bone, 2015. 80: p. 115-125.
