Staying healthy doesn’t require spending hours in the gym every day. According to medical experts, the right amount of weekly exercise may be far more achievable than most people think.

A new paper argues that exercise and protein guidelines should focus on thriving, not merely avoiding disease and weakness.

The evidence base consisted of 52 systematic reviews (42 for exercise, nine for diet, and one for weight management), and an additional 23 randomized controlled trials. The most commonly studied types ...