There is plenty of confusing messages out there on exactly how much exercise a week has the most health benefits. The NHS recommends 150 minutes of moderate physical activity, or 75 minutes of intense physical activity a week, but many people do more than that. Other studies have concluded that too much exercise can do harm, in particular to the cardiovascular system, leaving runners scratching their heads as to how much exercise is healthy.
So, those who are worried they are not doing enough – or too much – exercise should look closely at the release of a new study published in Circulation. The study tracked more than 115,000 US adults over 30 years of exercise and found that those who did more than twice (and up to four times) the recommended amount of exercise a week lived longer.
Interestingly, the study also found that 600 minutes (10 hours) of exercise a week was the cut-off point for seeing lower mortality rates. Anything above that amount did not result in any additional reduction in risk of death and, more importantly for high-volume runners, they also did not find any negative effects – in particular to the heart – associated with that amount of exercise.
"This finding may reduce the concerns around the potential harmful effect of engaging in high levels of physical activity observed in several previous studies," said Dong Hoon Lee, a research associate in the department of nutrition at the Harvard TH Chan School of Public Health in Boston.
Researchers found that 300-600 minutes of moderate exercise per week had a 26-31% lower risk of mortality from all causes, and people who performed 150-300 minutes of vigorous physical activity a week had a 21-23% lower risk. Those who follow current guidelines of 75 minutes of vigorous exercise a week, meanwhile, had a 19% lower risk.
