His results show that even small amounts of exercise contribute to substantial improvements in longevity and can reduce the risk of developing or dying from heart disease and many types of cancer.
“The investigators have thoroughly reviewed the available evidence and have provided encouraging results,” said I-Min Lee, professor of epidemiology at Harvard TH Chan School of Public Health, who was not involved in the new study. .
Perhaps most inspiring, the study’s statistical analysis suggests that 1 in 10 premature deaths could be prevented if each of us got up and moved even a little more than many of us currently do.
150 minutes versus 75 minutes per week
For years, government health agencies in the United States, Canada, Europe and other countries have recommended that anyone able to exercise exercise moderately for at least 150 minutes a day. week for optimal health. (Moderate exercise means brisk walking or similar efforts that raise your heart rate and breathing enough to make talking difficult.)
Concretely, these instructions recommend a brisk walk of half an hour five times a week.
But most of us don’t, according to the latest federal statistics, which show that only about 47 percent of American adults get enough exercise.
This sobering statistic prompted some researchers to begin studying the effects of small amounts of exercise. Most of the resulting research, however, has involved relatively small numbers of people, making general conclusions about the best doses of exercise elusive.
So for the new study, researchers from the University of Cambridge, Queen’s University Belfast and other institutions decided to pool data from as many relevant previous studies as possible, creating a pool of much larger participants and potentially more convincing results.
They ended up with 196 studies, covering more than 30 million people, making it, by many measures and a considerable margin, “the largest” study of how exercise contributes to longevity, said Leandro Garcia. Garcia is a public health and complexity researcher at Queen’s University Belfast who led the new study.
Big gains by moving just a little more
What the aggregate data has shown is that 150 minutes of moderate weekly activity should remain our benchmark for exercise. People who put in as much effort were about 31% less likely to die prematurely than people who were inactive.
But since two-thirds of the more than 30 million participants didn’t exercise much, the researchers also looked at the impacts of decreased movement. Of course, the impacts have been significant. Men and women who accumulated only 75 minutes of moderate exercise per week, or about 11 minutes per day, were 23% less likely to die prematurely from any cause than people who moved less.
Those 11 minutes of daily exercise also reduced the risk of heart disease by 17% and cancer of any kind by 7%. For some cancers, including myeloid leukemia, myeloma and some stomach cancers, the risk was reduced by 26%.
Perhaps most convincingly, the scientists also used statistical modeling to estimate that 16%, or 1 in 6, of all premature deaths would not occur if nearly everyone exercised 150 minutes a week. , in accordance with current guidelines.
Even if everyone walked just 11 minutes a day, 1 in 10 premature deaths could be avoided, they concluded.
“We already knew that doing physical activity was better than doing nothing,” Garcia said. “However, due to the size of our study, we were able to establish this association more precisely.”
The study, in fact, tells us that “the best value for money occurs when someone goes from doing nothing to even half of the recommended levels of exercise,” Lee said.
Despite its size and rigor, the study has significant limitations. It shows correlations between more movement, longer lives and less disease, but not whether exercise directly causes these gains. Other factors, such as genetics and income, likely play an important role. Aggregate studies have also relied on people’s recollections and reports of how much exercise they do, which may not be reliable.
But even with those downsides, the results provide a useful boost, Garcia said. “Adding physical activity to your daily routine doesn’t have to be daunting,” he said. “Small, gradual changes are a great start and will bring a range of health benefits.”
Park a little farther from your office, he says. Take the stairs. Dance in the living room with your children.
Ideally, aim for about 11 minutes a day of moderate movement to start with, he said, and if you find that amount “manageable,” then “try increasing it gradually to the recommended amount” of 150 minutes a day. week. But in all circumstances, he said, “doing physical activity is better for your health than not doing any at all”.
Do you have a fitness question? E-mail YourMove@washpost.com and we may answer your question in a future column.
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