The question of how much vigorous activity we should get has made for some hot debates in recent years. Some studies have suggested that we should routinely engage in vigorous exercise to prevent chronic diseases and early mortality; others have suggested that moderate exercise, but more of it, is just as good. Others have even argued there’s an upper limit to the strenuousness of exercise, beyond which its stress on the body may negate its benefits. But now, a large new study in JAMA Internal Medicine suggests that indeed vigorous exercise, regardless of body weight or chronic disease status, can reduce early mortality significantly. And the authors suggest it may finally be time to change those exercise recommendations that are standard in pretty much every corner of the globe.
The researchers from James Cook University and the University of Sydney looked at data tracking over 204,000 participants, 45 and older, for an average of six and a half years. They were divided into three groups: those who engaged in only moderate activity, like leisurely swimming, social tennis, or even household chores; and people whose activity was vigorous (jogging, aerobics, or competitive tennis) up to 30% of the time, or more than 30% of the time.
People who exercised vigorously up to 30% of the time had a 9% reduced risk of dying; those whose exercise was vigorous more than 30% of the time reduced their mortality risk by 13%.
The researchers controlled for a number of variables, like BMI, diet, age, alcohol use, and whether the person had a chronic illness like diabetes or heart disease. And the mortality benefit was still there.
"The benefits of vigorous activity applied to men and women of all ages, and were independent of the total amount of time spent being active," said lead author Klaus Gebel. "The results indicate that whether or not you are obese, and whether or not you have heart disease or diabetes, if you can manage some vigorous activity it could offer significant benefits for longevity."
Most guidelines say that two minutes of moderate activity offers about the same health benefit as one minute of vigorous activity – but this assumption may need to be changed, given what researchers are learning about the relative benefits of each. “The current physical activity guidelines from the World Health Organization, and those for the US, UK, Australia and other countries,” says Gebel, “recommend that adults should accumulate at least 150 minutes of moderate physical activity per week or 75 minutes of vigorous activity or a combination of both in which 1 minute of vigorous activity counts as much as 2 minutes of moderate activity. So these guidelines leave individuals to choose their activity patterns according to their preferences and abilities.” But it may be more complex than this, he adds. Vigorous exercise may not give just twice the bang for the buck as moderate exercise; it may actually give a lot more.
Gebel points out that one way to get some vigorous exercise, but also enjoy recovery periods, is to do some high intensity interval training. Research has shown it to be beneficial to people with even chronic health problems, he says. And you don’t have to push it to 11. “The physical activity guidelines from the US Department of Health and Human Services define vigorous activity relative to an individual’s personal capacity as a 7 or 8 on a scale of 0 to 10, so the activity does not need to be extremely vigorous.”
Always talk with your doctor if you’re thinking of revving up your exercise routine, especially if you have a chronic health issue. But if you’re already engaging in vigorous exercise – the caveat being that you should always listen to your body closely – it’s probably fine to carry on.
