There are three ways to look at battling cancer. For those who don’t have it, lowering risk is the primary goal. For those who’ve had it, successfully recovering and, of course, reducing the chances of recurrence are of utmost importance. For those who currently have it, the priorities are getting rid of it and minimizing the harmful effects that both the disease and the treatment have on the body. Exercise has been shown to help with all three.

Mark P. Kelly, PhD, CSCS, owner of Principle-Centered Health and teacher of exercise physiology at Irvine Valley College and Santa Ana College in California, explains how exercise can be beneficial in these three instances.

Prevention

Exercise is a key component in cancer prevention and control efforts (Moore et al. 2016). Physical activity is associated with a lower risk of 13 types of cancer, according to recent findings.

Reductions in colon, breast and endometrial cancers are well-studied and documented. Additionally, a meta-study pooled data on 1.44 million people and followed participants a median of 11 years, with 187,000 new cases of cancer occurring. Researchers found that exercise lowered the risk of many cancers, with the greatest risk reductions occurring for esophageal adenocarcinoma, liver and kidney cancers, and myeloid leukemia. The associations were generalizable to different populations, including people with excess weight or obesity and those with a history of smoking (Moore et al. 2016).

Another way exercise can help prevent cancer? About 500,000 cancer cases each year are attributed to obesity (McTiernan 2006), and exercise can help people obtain a healthy weight. Studies show that high-intensity interval training (HIIT) burns more fat and calories and lowers blood sugar levels more effectively than moderate exercise. And HIIT training seems to alter the hormonal milieu and lower the amount of estrogen that fat cells produce, thus dampening the risk for estrogen-sensitive cancers.

Studies have also shown those who exercise early in life have reduced chances of breast cancer later in life. Chinese women who exercised an average of 70 minutes per week during their teens reduced their chances of dying from cancer by 16%, and those who kept exercising as adults had a 20% lower risk of premature death from all causes, compared with other women (Nechuta et al. 2015).

During Treatment

If you are diagnosed with cancer, exercise can help during treatment. It has been shown to minimize the negative effects of conventional cancer therapy. A meta-analysis of 16 studies found that cancer patients who exercised had consistently better quality of life, compared with their nonexercising counterparts (McTiernan 2006). The benefits were both physical and mental and included less fatigue, more energy, fewer hospital stays and doctor visits, and higher self-esteem.

Taking an “active approach” to fighting cancer is indeed the best choice. In a 2005 Harvard study, breast cancer patients who exercised at moderate intensities 3–5 hours per week lowered the odds of dying from cancer by about half, compared with sedentary patients (Holmes et al. 2005). Even a little exercise improved patients’ odds, regardless of stage or diagnosis timing.

After Treatment

Exercise can also help after cancer treatment is finished. A report from the Memorial Sloan Kettering Cancer Center stated, “Multiple studies show that regular physical activity is linked to increased life expectancy after a diagnosis of cancer, in many cases by decreasing the risk of cancer recurrence.” The World Cancer Research Fund, American College of Sports Medicine, and U.S. Department of Health and Human Services all advocate physical activity for cancer patients and survivors (Grisham 2014).