Getting recommended amounts of physical activity is linked to a lower risk for 7 cancer types, according to a study from the American Cancer Society, the National Cancer Institute, and the Harvard T.H. Chan School of Public Health.
Health experts have known for a long time that exercise is linked with a lower risk of several cancers, but they’ve had limited evidence about how much exercise is needed. The new study found that the equivalent of 2.5 to 5 hours of moderate-intensity activity per week (or 1.25 to 2.5 hours of vigorous activity) provided a significant benefit. The study was published December 26, 2019 in the Journal of Clinical Oncology.
“This paper provides some of the most robust evidence to date that in fact meeting current physical activity recommendations is sufficient for 7 different types of cancer prevention,” said Alpa Patel, PhD, co-author of the study and senior scientific director of epidemiology research at the American Cancer Society.
The researchers looked at 9 prospective studies involving more than 750,000 adults with an average age of 62, who answered questions about how much leisure-time physical activity they got. This is time spent outside of work on activities for the purpose of getting exercise, such as playing a sport, working out, or taking a walk. Moderate-intensity activities are at about the level of a brisk walk. They burn 3 to 6 times as much energy measured in terms of metabolic equivalent tasks (METs) as sitting quietly. Vigorous-intensity activities burn more than 6 METs.
The study found that getting recommended amounts of activity (7.5 – 15 MET hours per week, which equates to 2.5 – 5 hours of moderate-intensity activity or 1.25 – 2.5 hours of vigorous activity) significantly lowered the risk for 7 of the 15 cancer types studied: colon, breast, endometrial, kidney, multiple myeloma, liver, and non-Hodgkin lymphoma. Getting more MET hours was associated with an even greater reduction in risk for some of the cancer types.
Specifically, physical activity was linked with:
The authors conclude that adults should get physical activity at recommended levels to lower risk of cancer. Patel says most adults can meet the recommendation by walking 30 minutes a day at a rate of 3 miles per hour.
Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.
Amount and Intensity of Leisure-Time Physical Activity and Lower Cancer Risk. Published December 26, 2019 in Journal of Clinical Oncology. First author Charles E. Matthews, PhD, National Cancer Institute, Bethesda, Md.