While it’s true that some exercise is better than none, it is also true that the more you do the better it is for you. New study data published by the American Heart Association shows people who exercise twice as much and up to four times the recommended weekly amount have a significantly reduced risk of mortality.
The current recommendations from the American Heart Association based on guidance from U.S. Department of Health and Human Services is 150 minutes of moderate physical activity per week or 75 minutes of vigorous physical activity per week or some combination of the two.
Analyzing the data of more than 100,000 study participants over a 30-year follow up period, researchers at Harvard found those who engaged in two-to-four times the recommended amount for moderate physical activity had a reduction in mortality risk of 26-31%. Those who exceeded the amount of recommended vigorous activity between a factor of two to four saw a reduction in mortality between 21-23%.
"The potential impact of physical activity on health is great, yet it remains unclear whether engaging in high levels of prolonged, vigorous or moderate intensity physical activity above the recommended levels provides any additional benefits or harmful effects on cardiovascular health," said Dong Hoon Lee, Sc.D., M.S., a research associate in the department of nutrition at the Harvard T.H. Chan School of Public Health in Boston. "Our study leveraged repeated measures of self-reported physical activity over decades to examine the association between long-term physical activity during middle and late adulthood and mortality."
Study participants self-reported their leisure time and physical activity through a questionnaire that was repeated every two years. The questionnaire included general health information as well as physician-diagnosed illnesses, family medical histories, drinking and smoking habits and frequency of exercise. Moderate activity was defined as walking, low-intensity exercise, weightlifting and calisthenics, while vigorous physical activity was characterized by jogging, running, swimming, bicycling and other aerobic exercises.
Researchers observed decreased risk of cardiovascular disease mortality, non-cardiovascular disease mortality and all-cause mortality in those who exceeded the minimum activity levels. They also observed no noticeable risks of exceeding the exercise recommendations. However, they also noticed no observable difference in those who went above four-times the recommended weekly exercise threshold.
"Our study provides evidence to guide individuals to choose the right amount and intensity of physical activity over their lifetime to maintain their overall health," Lee said. "Our findings support the current national physical activity guidelines and further suggest that the maximum benefits may be achieved by performing medium to high levels of either moderate or vigorous activity or a combination."