Exercise is good work for body, mind and health. It can also improve longevity by as much as 30 per cent.
But, the question of how much exercise is enough and how much is too much remains a hot topic of debate. Guidelines tend to suggest that the ideal type of exercise is about five to seven days a week at a moderate level.
Now, in a new study published in the Journal of the American College of Cardiology, researchers believe they have an answer of sorts.
Researchers from Denmark found that those who ran at a fast pace for more than four hours a week had the same statistical rate of dying as the sedentary participants. To come to this conclusion, they compiled more than 1000 regular exercisers and nearly 4000 healthy, sedentary people and followed them over a 12-year period.
The light joggers, who exercised two to three times a week for between one and 2.4 hours a week, had the lowest risk of dying. The moderate runners, who worked out two to three times a week for up to four hours, had a slightly higher risk, which came as a surprise to the researchers.
“I would expect the light joggers to have really low risk,” Jacob Marott, a researcher at the Copenhagen City Heart Study at Frederiksberg Hospital and one of the study’s co-authors, told Time.
“But regarding the moderate joggers, I was a little surprised they didn’t have a bigger benefit from jogging than the light joggers. It made me think that if it’s really true, then exercise recommendations should take that into account.”
Shifting Messages
Many health and fitness professionals are indeed shifting their recommendations to correspond with the latest research. The less is the message, supported in this new study, which coincides with emerging research that short, sharp workouts might be more beneficial than long, laborious workouts. Less, of course, does not mean anything at all.
Associate Prof. David Dunstan, head of the Physical Activity Laboratory at Baker IDI Heart and Diabetes Institute, says the study confirms an important point. “The key message is that doing something is better than doing nothing,” he says, but “if you’re doing a hell of a lot of exercise you may be predisposing yourself to increased risk.”
That said, Dunstan points out that the study is not definitive. There were only about 50 of the study’s participants who did more than four hours of intense exercise a week, compared with about 600 who did light or moderate exercise.
This could be an influence on the statistics, Dunstan says, noting that researchers also made assumptions that participants kept up the same level of exercise over the entire 12 years. Besides, working out too much is hardly a problem for most of the population. “Very few people are doing vigorous exercise and only about two per cent are doing that high-intensity exercise.”
