Lowest Risk of Death In Adults Who Exercise Four Times More Than Recommended Minimum

The results of a new study show that adults who exercised two to four times longer than the recommended minimum amount of physical activity had a significantly lower risk of death from all causes.

The results are published in the peer-reviewed journal Circulation.

The health benefits of exercise

The benefits of physical activity are well documented, with regular exercise being strongly associated with reduced risks of developing conditions such as cardiovascular disease (CVD). Guidelines from 2018 issued by the United States Department of Health and Human Services stated that adults should achieve at least 150–300 minutes of moderate physical activity or 75–150 minutes of vigorous physical activity each week. Nevertheless, it remains unclear whether there is evidence that supports long-term moderate or vigorous exercise being associated with lower mortality.

The current study sought to address this by analyzing the medical records and mortality data from over 100,000 adults, collected from two large studies over a period of 30 years – the all-female Nurses’ Health Study and the all-male Health Professionals Follow-Up Study. Of the participants taken forward for the study, 63% were female and over 96% were white, with an average age of 66 years and an average body mass index (BMI) of 26 kg/m² over the 30-year follow-up period.

Participants were asked to self-report their spare-time physical activity via a validated questionnaire every two years. This also included questions on their health, diagnosed illnesses, family histories and lifestyle habits such as cigarette smoking or alcohol consumption. Data on exercise was documented as the average weekly time spent on different types of physical activity over the previous year. Researchers classified moderate physical activity as activities such as walking, weightlifting and calisthenics, whereas vigorous activity was classed as jogging, running, swimming and other aerobic exercises such as cycling.

Donghoon Lee, a research associate at the Harvard T.H. Chan School of Public Health in Boston and the lead author of the study, explained, “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. 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.”

Physical activity reduces all-cause mortality

The study found that those who performed the currently recommended duration of moderate activity (150–300 minutes per week) or vigorous physical activity (75–150 minutes per week), had a 20–21% and 19% lower risk of mortality from all causes, respectively. Furthermore, those that exercised for over twice the currently recommended duration each week had the lowest long-term risk of mortality. For moderate activity, those performing two to four times the recommended amount each week had a 26–31% reduction in all-cause mortality, whilst those performing two to four times the amount of vigorous activity had a 21-23% reduction.

Aside from all-cause mortality, researchers also looked at data regarding cause-specific mortality such as CVD. Those who met the guidelines for moderate activity had a 22–25% lower risk of CVD mortality, and those exceeding it had 28–38% reduced risk, while for vigorous activity the recommended duration was associated with 31% reduced CVD death risk, and exceeding it reduced risk by 27–33%.

Researchers also examined the risks associated with those that performed over four times the recommended minimum amount of activity, as previous data suggested that long-term levels of high-intensity endurance exercise such as marathons and triathlons may be associated with cardiovascular events including atrial fibrillation and sudden cardiac death. However, the current study concluded that there was no association with these adverse events. “This finding may reduce the concerns around the potentially harmful effect of engaging in high levels of physical activity observed in several previous studies,” Lee elaborated. However, there was no evidence that performing over four times the weekly minimum provided any further reduction to all-cause mortality.

Lee concluded by saying, “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. 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.”

Reference: Lee DH, Rezende LFM, Joh HK, et al. Long-term leisure-time physical activity intensity and all-cause and cause-specific mortality: a prospective cohort of US adults. Circulation. 2022;0(0). doi: 10.1161/CIRCULATIONAHA.121.058162

This article is a rework of a press release issued by The American Heart Association. Material has been edited for length and content.