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The benefits of exercise are so great that if it were a drug, it would be a miracle cure. But what’s the optimal dosage for better health? Is someone who runs ultramarathons, lifts weights every day, or swims the English Channel better off than someone who just goes for a leisurely walk? And is it possible to overdose? Now, thanks to a large-scale study following a group of people over a long period of time, we finally have the answers.
First, these studies show dose-related effects of exercise, meaning that health benefits appear even at low levels of activity. For example, a 2022 study that followed more than 400,000 US adults for nearly 20 years found that one hour of aerobic exercise per week was associated with a 10-20% lower risk of death over the study period (see the “Health Gains” graph below).
The good news for sedentary people is that the greatest benefits come from switching from doing nothing to doing something, and for a given amount of exercise, the health benefits for people over 60 appear to be greater than for younger adults.
You can also explore the effects of different intensities of physical activity. Moderate-intensity activity is activity that gets your heart rate up significantly, like a brisk walk or playing a fun game.
