Just like eight hours of sleep per night is the magic formula for optimum health, 30 minutes of daily activity is generally regarded to be a sweet spot when it comes to exercise and health. But if you can't swing that, you're supposed to at least hit the minimum recommended amount of weekly exercise: 150 minutes of moderate activity per week, which breaks down to 21 minutes of moderate cardio per day. They say it is the key to weight loss and a better life, but how do we know? General health and maintenance aside, how much exercise do you need to actually extend your life span? The scientific community hasn't had a clear sense of this—until now. Keep scrolling to find out the stats!
Two large-scale studies published in JAMA Internal Medicine directly tackled the longevity question—with some seriously fascinating results. For one of the studies, researchers with the National Cancer Institute, American Cancer Society, Harvard, Johns Hopkins Bloomberg School of Public Health, and other institutions looked at the aggregated results of six large ongoing health surveys in which people self-reported how much exercise they do per week. With the pooled data, they were able to study the exercise habits of more than 660,000 adults and categorize them based on their level of activity: those who don't exercise at all, those who exercise some but still less than the recommended weekly amount of 150 minutes of moderate cardio, those who exercise two to three times more than the recommended amount, and others who exercise upward of three to five times that.
They were also able to study 14 years' worth of death records for the group and found that those who exercised less than the recommended amount still had a 20% lower mortality risk than those who didn't exercise at all—which confirms the old adage that every little bit counts. This means that even if you're exercising less than 21 minutes a day or 150 minutes per week, you're giving yourself a 20% lower risk of death than if you weren't exercising at all. Those who exercised one to two times the minimum recommended weekly amount (300 minutes of moderate cardio per week, which breaks down to about 42 minutes of moderate cardio a day) had a 31% lower risk of mortality, those who exercised two to three times the minimum recommended amount had a 37% lower rate, and those who exercised three to five times the minimum had a 39% lower rate.
The bottom line? Science shows that if you aim to do moderate cardio for about 45 minutes a day, you can lower your risk of an earlier death by 31%—and you can reduce it by 39% if you exercise moderately for just over one hour a day (64 minutes). We think that's pretty darn doable, considering the impact it has on your life span!
The second study looked at vigorous versus moderate exercise and how much of an increase in life span one gets from doing spurts of vigorous exercise instead of sustained moderate exercise. It found that among groups of people who meet the recommended guidelines for exercise each week, those who categorized at least 30% of their exercise being vigorous had a 9% lower risk of mortality than those who only do moderate exercise all week, and if more than 30% was vigorous, the lowered risk went from 9% to 13%. The takeaway? The numbers are most stacked in your favor if you work out for an hour a day per week and if more than 30% of your weekly exercise is vigorous.
But as always, your should consult your physician before starting a new workout program, especially a vigorous one. Fitness expert Christine Bullock notes that you should remember that "too much exercise can also result in adrenal fatigue, and without rest days in between, your energy levels could tank and your body could become depleted. She adds that "20 minutes of daily movement is more than enough. There are so many workout apps available today that make it easy to do from home. A workout should be short and sweet enough to slip into your life seamlessly while still providing all the same benefits."
Arem H, Moore SC, Patel A, et al. Leisure time physical activity and mortality: a detailed pooled analysis of the dose-response relationship. JAMA Intern Med. 2015;175(6):959‐967. doi:10.1001/jamainternmed.2015.0533
Gebel K, Ding D, Chey T, Stamatakis E, Brown WJ, Bauman AE. Effect of moderate to vigorous physical activity on all-cause mortality in middle-aged and older Australians. JAMA Intern Med. 2015;175(6):970‐977. doi:10.1001/jamainternmed.2015.0541