Exercise can also reduce the risk of developing cancer in the first place.
We’re all conscious of the benefits of exercise for most people, but in recent years the scientific community has paid more attention to its potential benefits for the sick — and made some surprising discoveries.
While in the past doctors may have advised cancer patients to rest up, there’s now evidence that in cases across the cancer spectrum, exercise can moderate the progression of the disease, enhance the benefits of treatment, and improve patients’ physiological and psychological health. Many of the benefits of exercise are associated with its general health-promoting properties, but more and more data shows that physical activity can also have a positive effect on cancer specifically.
“Studies show that 150 minutes of weekly exercise dramatically improves survival,” Bente Klarlund Pedersen, clinical professor at the University of Copenhagen and head of its Centre of Inflammation and Metabolism, told The Washington Post. “It is becoming more and more evident that exercise can have more direct effects on cancer and its treatment.”
What sort of exercise is most effective?
According to Rob Newton, a professor of exercise medicine at Edith Cowan University in Australia who explained his findings to the Post, the type of exercise patients engage in is key, with vigorous activity most likely to yield results. For aerobic exercise — running, walking, cycling, etc, — this means that you should be breathing heavily, and unable to hold a steady conversation. If you’re doing resistance training, you should be using heavy weights — if you can lift them more than a dozen times, they’re too light.
Research published in Science Direct shows that consistent, relatively intense exercise can inhibit the development of tumors in several ways. It can control the progression of cancer through direct effects on tumor growth rate, metastasis, metabolism, and immunogenicity (a tumor’s ability to prompt an immune response). Exercise can also regulate tumor growth, alleviate adverse events related to cancer and its treatment, and improve the efficacy of cancer treatment.
The latest treatment guidelines presented at the American Society of Clinical Oncology’s annual conference state that doctors should also recommend aerobic exercise, like walking, swimming or running, to minimize the negative side effects of cancer treatment.
“Exercise interventions during active treatment reduce fatigue, preserve cardiorespiratory fitness, physical functioning, and strength and in some populations, improve quality of life and reduce anxiety and depression,” the guidelines say.
Exercise and cognitive function
Some research shows that physical activity can help to arrest the cognitive decline often associated with cancer. One study showed that exercise was associated with better cognitive function both immediately following chemotherapy treatment, and 6 months later. Another focused on the effects of exercise on breast cancer patients who underwent chemotherapy, finding that while tested cognitive function didn’t improve for all patients, it did have a positive effect for highly fatigued patients. Self-reported cognitive functioning, physical fitness, fatigue, quality of life, and depression improved for patients across the continuum.
Exercise as a means of prevention
“Today, exercise is so well accepted for its wide range of physical and mental health benefits that it is sometimes hard to fully appreciate the earlier days, when so many aspects were still unknown and we were working through the research methods,” Graham Colditz, who has been studying the relationship between exercise and cancer for more than 30 years, told The Washington Post.
Colditz has been at the forefront of research upending those long-held beliefs. In 1999, he led a study that demonstrated that women who engaged in moderate or vigorous physical activity for 7 or more hours per week were nearly 20% less likely to develop breast cancer than those who exercised for less than an hour per week.
Exercise has important effects on hormone function, inflammation in the body, and blood flow — all of which can reduce the risk of developing cancer. There’s also strong evidence that maintaining muscle mass through exercise (and preventing fat gain can) is associated with a greater chance of survival in those who do develop cancer.