Pedro Saint-Maurice, a postdoctoral fellow at the National Cancer Institute of the National Institutes of Health (NIH), and his colleagues wanted to find out whether exercise’s benefits changed if people remained active for most of their lives, or if, like most of us, they waxed and waned in sticking to their exercise regimen over their lifetimes.
In a study published in JAMA Network Open, they asked more than 315,000 U.S. adults — between ages 50 and 71 — about their leisure-time activity at four different points in their lives: when they were 15-18 years, 19-29 years, 35-39 years and 40-61 years.
People who said they exercised anywhere from two to eight hours a week at each time period had a 29% to 36% lower risk of dying from any cause during the study’s 20-year period, compared to people who rarely or never exercised. They also lowered their risk of dying from heart disease by up to 42% and cancer by up to 14% compared to inactive people. The more people exercised, the greater their risk reductions.
Given the many health benefits of exercise, that’s not shocking. But Saint-Maurice was surprised when he looked at people who were not active when they were younger, but who increased their exercise levels after their 40s beyond levels they had when they were younger. They also showed declines in their risk of dying early that were similar to those of people who exercised consistently throughout their lives — a drop of 32% to 35% compared to people who didn’t exercise. Drops in heart disease and cancer risk were similar to the steady exercisers, too. For these people as well, those who increased their exercise levels the most saw the greatest benefits.