US Olympian Maya DiRado is definitely getting the benefits of exercising. Al Bello/Getty Images You don't have to work out that long to reap the many health benefits of exercise.

A study published in the Viewpoints section of JAMA reviewed the existing evidence and concluded that this magic number — how long you need to exert yourself to see results — is merely minutes.

The authors wrote that 15 minutes of daily moderate activity was associated with a reduced risk of early death, and running for five to 10 minutes per day was associated with a reduction in the risk of early death due to heart disease in particular.

That's less than the weekly 2.5 hours of moderate intensity or 1.25 hours of vigorous intensity exercise that the US Centers for Disease Control and Prevention recommend — but still more than what most American adults actually do.

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While doing more than the bare minimum of physical activity may lead to more noticeable results, the JAMA paper suggests that even a small, regular amount of exercise is enough to make a difference.

"For vigorous physical activity, low doses are related to large benefits," the authors write in the study. Setting aside those minutes is worth your while.

Countless other studies have identified the many benefits that regular exercise can give you. It has been linked to lower risks of heart disease, depression, dementia, diabetes, and even some cancers — not to mention it can make you look and feel great.

There's even an exercise limit

The authors of the JAMA review also looked at the upper limit for when exercising more no longer shows significant health benefits.

They found that exercising moderately for more than 100 minutes per day didn't show any more reduced mortality rates, and neither did exercising vigorously for more than 12.5 hours per week.

This, of course, doesn't mean that more exercise is bad for you, the authors note, but merely that it probably isn't any better for you at those extreme limits. Only physical inactivity has shown negative health effects.

Overall, the paper is encouraging, suggesting that casual exercisers should keep it up while super-intense exercisers have no reason to gloat.

"Although lack of time is a critical barrier to engaging in physical activity," the researchers write, "these results suggest that even the busiest individuals should have time for this lowest effective dose of physical activity."