How many steps should people take every day for good health?
A new study of activity and mortality in older women finds that the total could be lower than many of us expect and that even small increases in steps can be meaningful. The study also side-eyes the validity, utility and origin of the common 10,000-step-a-day exercise goals built into so many of our phones and activity monitors and suggests, instead, that any moving, whether or not it counts as exercise, may help to extend people’s lives.
By now, almost all of us know that walking and other types of physical activity are indispensable to our well-being. Studies show that active people have lower incidences of heart disease, obesity and Type 2 diabetes and usually live longer than people who are sedentary. But many of us remain confused about just how much exercise we need and how intense it should be.
The official exercise guidelines in the United States and many other nations recommend that adults complete at least 150 minutes a week of moderate exercise, such as walking. These guidelines are based, for the most part, on past studies linking the length of time people are active with their subsequent robust or poor health.
But some scientists have begun to suspect that telling people to measure their workouts in minutes may not be ideal.
“People may not intuitively grasp what 150 minutes a week of exercise means in practical terms,” says I-Min Lee, a professor of medicine at Harvard University, who led the new study.
Step counts are a simpler, more concrete and convenient measure of physical activity, she says. We can understand the concept of a step and how to add them up. And, helpfully, many of us possess technology in our phones or activity monitors that will count our steps for us.
But few past studies have correlated steps and health, largely because such research requires people to wear activity monitors and not just tell researchers how often they exercise.
So, for the new study, which was published last week in JAMA Internal Medicine, Lee and her colleagues set out to objectively quantify how many steps might be needed to avoid premature mortality.
Many of us likely assume that the answer is 10,000, since so many of our activity monitors use that threshold as a goal. But no scientific evidence supports that idea, Lee says. The concept of 10,000 steps seems to have originated, in fact, with a Japanese clock maker in the 1960s, she says. It gave its consumer pedometer a Japanese name that translates as “10,000 steps,” and somehow that ideal took hold. (Some past research suggests that we might need to take more than 10,000 steps to protect ourselves against heart disease.)
Now, aiming instead to use science rather than semantics, Lee and her colleagues began trolling through the massive data from the Women’s Health Study, which has been tracking the health and habits of older women for decades.
As part of that study, thousands of older women had worn a sophisticated activity monitor for a week. It tracked the steps each woman took per minute throughout the day.
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