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A cancer diagnosis used to come with the suggestion to “rest.” However, now science has proven what our bodies have always known—moving is good for us! The American Cancer Society even recommends cancer patients strive for five 30-minute fitness sessions and two strength-training workouts per week, with modifications for type and stage of cancer.
In addition to the proven benefits of regular activity promoting a healthy heart and bones and boosting mental outlook, exercise helps cancer patients combat nausea and treatment-related tiredness (counterintuitive, but true).
New research from Bradley Behnke, an associate professor of exercise physiology, and his team at Kansas State University indicates moderate exercise may help some cancer treatments, such as radiation, be more effective.
“If we can increase the efficacy of radiation treatment, then the patient’s prognosis is enhanced,” Behnke explains. “An intervention like exercise has almost universally positive side effects versus other treatments that can have deleterious side effects. Exercise is a type of therapy that benefits multiple systems in the body and may permanently alter the environment within the tumor.”
Behnke was curious as to how tumors would respond during and after exercise. He discovered that many tumors prefer oxygen-deprived environments. Exercise improves blood flow, in turn improving oxygenation throughout the body, even to hard-to-reach-and-treat tumors. These findings resulted in Behnke and his team receiving a grant from the American Cancer Society to study moderate exercise as a method for making radiation treatments more effective.
“If we manipulate all the systems in the body—the lungs, the heart and the blood vessels—with exercise, we can take advantage of the dysfunctional vasculature in the tumor and enhance blood flow to the tumor,” Behnke explains. “The tumor becomes the path of least resistance for the elevated cardiac output of exercise, which results in a substantial increase in tumor oxygenation during and after exercise.”
For hard-charging runners, it may be challenging to keep effort level at “moderate.” Intensity needs to be harder than an easy walk, but not so hard that you can’t carry on a conversation, in the neighborhood of 30 to 60 percent aerobic capacity. Think: Jog instead of doing a tempo run. If you go too easy, blood flow won’t be stimulated enough. Exercising too vigorously may cause undue exhaustion (according to the National Comprehensive Cancer Network, NCCN) and possibly impede blood flow to the tumor or further tax the immune system, according to Behnke.
Consult with your doctor before beginning a physical fitness regiment. The type and stage of your cancer may affect what you are able to do. In addition to drinking plenty of water and warming up before you exercise, the NCCN advises patients to listen to their bodies and avoid exercise if they have a fever or do not feel well.
The study was published in the Journal of the National Cancer Institute, can be read here.