A NEW analysis of data from nearly 200 studies has found that just 75 minutes of moderate physical activity per week can have a substantial impact on the risks of early death, cardiovascular disease, and certain cancers.
The analysis, published in the British Journal of Sports Medicine, is the largest of its kind and found that one in 10 early deaths could have been prevented if everyone had met just half the recommended weekly target of 150 minutes of moderate-intensity physical activity.
The researchers developed a new framework that enabled them to compare studies measuring and reporting physical activity in many different ways and exclude resting energy expenditure. They also explored the dose-response links between leisure time physical activity and specific types of cancer for the first time.
The analysis pooled the results of 196 studies of more than 30 million people.
Most of the participants reported leisure time physical activity below 17.5 metabolic equivalent of task (MET) hours per week, equivalent to 300 minutes of moderate-intensity physical activity.
In general, the analysis showed that higher levels of weekly physical activity were associated with a lower risk of all outcomes.
Differences in risk were greater between 0 and 8.75 weekly MET hours, equivalent to the recommended 150 minutes per week of moderate physical activity, with smaller marginal differences in risk above this level up to 17.5 MET hours per week.
Compared with inactive adults, those clocking up 8.75 MET hours per week had 31% and 29% lower risks of death from all causes and from cardiovascular disease, respectively. The difference in the risk of death from any cancer was 15%. The risk of cardiovascular disease was 27% lower, but the associations were weaker for different types of heart disease, with the strongest reduction observed for coronary heart disease: 21% lower risk.
The researchers estimated that if all insufficiently active people had managed 8.75 MET hours per week, almost 16% of all recorded premature deaths would have been prevented. Notably, 10% of all deaths would have been prevented if everyone clocked up just 75 minutes of moderate-intensity physical activity per week.
The researchers acknowledge that the included studies relied on self-reported physical activity levels, and they sometimes had to make assumptions about the intensity and duration where these weren’t explicitly reported. However, they conclude that “appreciable population health benefits might be gained from increasing [physical activity] levels of people who are inactive to just half the current health recommendations, with further benefits for all reaching at least the recommended level, and smaller additional benefits beyond that.”
