What’s the minimum amount of exercise we need each week?

A recent study conducted by scientists around the world concludes that you don’t need that much physical activity each week to gain substantial health benefits.

The study enrolled nearly 72,000 people (most between 50 and 80 years old). All of them were free of diagnosed heart disease or cancer at the start of the study.

A strength of the study was that the amount of vigorous physical activity people did was tracked by a device that measured their actual level of activity. (Many past studies just relied on participants to report their physical activity, which can be inaccurate.) The study participants’ health was followed over the next five years.

Even the people who did only 15 minutes per week of vigorous physical activity had a 17% lower risk of death from any cause and death from cancer compared with people who were inactive. With about 50 minutes per week, death from any cause was reduced by 36%.

The reduction in risk of death from all causes, and death from cancer, was greatest in the first 40 minutes of vigorous physical activity per week. In contrast, death from heart disease continued to decline substantially with each additional minute beyond 40 minutes.

If vigorous physical activity doesn’t immediately appeal to you, moderate physical activity like brisk walking—for at least 150 minutes per week, and ideally 300 minutes per week—also has proven health benefits.

But if you’re up for at least trying some vigorous physical activity, aim for 40 minutes per week—unless you’re at increased risk for heart disease, in which case you should strive for more. Your activity does not have to be done all at once. It can be done in short bursts that add up over the week to your goal. Some of these short bursts can be things you are doing anyway, like climbing stairs.

Harvard Health Publishing

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