Want to Live Longer? For Just 30 Minutes a Day, Do Anything Else But Sit
"Exercise doesn't have to be done for hours at a time"
You don’t need an expensive gym membership or marathon workouts to be healthy, a new study says: Just get up and move for at least half an hour a day.
Plenty of research has found that too much sitting is linked to a range of health risks, from cardiovascular disease to early aging. But the new paper, published in the American Journal of Epidemiology, finds that replacing just 30 minutes of sitting with any kind of movement, every day, could help you live longer. Getting up for half an hour of light activity — like walking, when a person would usually be sitting — corresponded to an estimated 17% lower risk of early death. Higher intensity movement has a larger effect; the same amount of moderate or vigorous exercise corresponded to about a 35% lower mortality risk, the paper says.
“There used to be this whole notion of no pain, no gain — that exercise or activity has to hurt to reap benefits,” says study co-author Keith Diaz, an assistant professor of behavioral medicine at Columbia University Irving Medical Center. But the latest research suggests that “exercise doesn’t have to be done for hours at a time. It’s something that anyone can do. It just requires walking, even for short periods of time.”
Of course, more exercise is still better. Diaz and his colleagues found that longevity benefits compounded as physical activity piled up; an hour of exercise conferred twice as many benefits as half an hour. But there appeared to be a point — around 3.5 hours of movement per day — at which people maxed out their gains from exercise. “If you move enough, there’s a threshold at which you’ve tipped the scale, and our risks from sitting are eliminated,” Diaz says.
The study used data from almost 8,000 healthy Americans who were older than 45 and who had worn physical activity trackers for at least four days as part of a separate study. The researchers used this data to calculate how much time people spent being sedentary versus active, and tracked people’s health and mortality data over more than five years of follow-up. They then created simulations that approximated how adding more movement — and thereby cutting down on sedentary time — could affect mortality risk.
The researchers found that even modest increases in physical activity contributed to a lower risk of death. And, they found, these chunks of movement were just as impactful if they accumulated little by little, rather than during one longer session.
“We used to think that exercise had to be done at a moderate or vigorous intensity. We used to think it had to be done in 10 minutes or more at a time,” Diaz says. “Our results kind of shift the narrative a bit. A one-minute burst here and a one-minute burst there actually can still be healthful.”
One important limitation of the study, however, is that it was based on simulations and was not a trial in which people changed their behavior and researchers observed the effects; that kind of experiment is the next step, Diaz says. But the researchers did go beyond many prior studies by accounting for every part of people’s days, and modeling how changing the proportion of sedentary versus active time could affect health.
Diaz’s research joins many other recent studies in finding that small bouts of exercise make a difference. When the federal physical activity guidelines were updated last year, they also said that short bursts of movement could count toward the recommended 150 minutes of moderate or 75 minutes of vigorous activity per week.
Research suggests that many Americans aren’t even getting close to that point. A recent study found that a quarter of American adults sit for more than eight hours a day, and only 3% said they sat for less than four hours a day and exercised regularly. Only 23% of adults meet federal physical activity guidelines, according to the latest numbers.
For the average American adult, the message behind Diaz’ study is an important one. “Just getting up and moving a little bit, even at light intensity, could be enough to lower your risk,” he says.