More and more it looks like exercise can help us manage cancer. It can minimize symptoms, speed recovery, and reduce the incidence of recurrence. It might even prevent cancer, at least in some patients for some types of cancers. So, is exercise a magic pill?
Let’s start with the easy stuff. Exercise makes us feel better, even if we are in the middle of cancer and its treatment. Multiple studies have shown that exercise helps manage cancer fatigue, eases aches and pains and helps minimize the side effects of treatment. Patients with advanced lung cancer find they can breathe a little easier. Men on androgen-deprivation therapy for prostate cancer report reduced fatigue. Breast cancer patients on aromatase inhibitors feel less achy. And many patients who exercise find they have an improved sense of well-being, are better able to deal with daily life.
Exercise has even been shown to reduce anxiety and help us manage our cancer emotions. Maybe it’s the release of endorphins and other neurotransmitters when we get our heart rates up. Maybe it’s the increase in red blood cells that comes with demanding our bodies produce more oxygen when we exercise. Doctors aren’t sure yet why. But the evidence is mounting that moving makes us feel better, at any stage in the cancer process.
Researchers are also building the case that exercise is effective treatment for reducing recurrence of some types of cancer. Physical activity, particularly aerobic exercise, creates biologic and metabolic changes that protect against cancer. It lowers hormone levels, reduces insulin resistance and decreases inflammation. At the same time, it stimulates changes in the way our genes behave as they reproduce. This affects DNA repair and the aging process. Exercise also boosts the immune system. It reduces oxidative stress. That’s the burden on our bodies from using oxygen in the air we breathe and metabolizing food into energy—the natural “rusting” that ages us from the inside out. It even speeds up digestion time, which reduces the risk of colon cancer.
In fact, studies have found that exercise can help manage breast cancer. Patients who exercised 150-250 minutes a week at moderate intensity reduce their likelihood of death from breast cancer by 40 – 50%. (Note, hormone-receptor positive tumors appear to be more responsive to exercise than triple-negative tumors. Also, exercise seems more protective against post-, rather than pre-menopausal breast cancer.) Research with colorectal cancer patients has found similar improvements in long term health benefits from exercise. So have studies with endometrial cancer patients. This suggests that exercise may be beneficial in reducing recurrence of other cancers as well.Decreased body fat, and the lower levels of hormones such as estrogen and ghrelin that comes along with it, may be the driving force for these improvements.
Possibility of Prevention
More recently, researchers have begun investigating the preventative effects of exercise. One study conducted found that vigorous physical activity is associated with a lower risk of an aggressive and often deadly form of prostate cancer.It’s too soon to say if exercise was the cause, or merely correlated with some other factor in those who like to do vigorous exercise (such a genetic composition), but the findings were significant. While we wait for additional research on the preventative powers of exercise, it’s safe to say, time to get moving!
So how much exercise is enough?
Any type of physical activity is good, whether its cleaning the house or performing a physically demanding job. But for exercise to help manage cancer, the greatest benefits seem to come from moderate to vigorous activity. The goal is to get your heart rate up and sustain it at a higher than normal rate for at least 10 minutes at a time. Aim for a total of 150 to 300 minutes a week, or 75 minutes a week of vigorous activity. Exercise is considered moderately intense when you can talk to someone while you are doing it, such as brisk walking or biking at 10 – 14 mph. Running and biking at high speed are considered vigorous exercise, as is chopping wood and shoveling heavy snow. Weight training and balance/flexibility exercise are also important in maintaining overall physical health, although there is less research on their cancer-specific benefits.
The key is to start slow, push yourself a little every day, and stay within your ability. There is no point in exercising so hard one day that you can’t get out of bed the next! Most importantly, talk to your doctor about starting an exercise regimen that makes sense for you.
Effects of Physical Exercise in Non-Operable Lung Cancer Patients Undergoing Palliative Treatment, Wiskemann et al, Annals of Oncology, October 1, 2018.
Exercise Therapy for Symptom Management, Iyengar, et al, ASCO Post, October 25, 2018.
Exercise-induced Biochemical Changes and their Potential Influence on Cancer: A Scientific Review. Thomas et al, British Journal of Sports Medicine, December 2016.
Ibid, Iyengar, et al.
A Prospective Study of the Association between Physical Activity and Risk of Prostate Cancer, Pernar, et al, European Urology, 2018.