Counting Steps? Here's How Many You Need to Boost Health
Taking that often-cited 10,000 steps a day — or even slightly fewer — may indeed be enough to improve your health, a new study suggests.
Researchers found that among 6,000 middle-aged and older adults, those who got at least 8,000 to 9,000 steps daily had reduced risks of developing an array of conditions over seven years. The list included obesity, high blood pressure, diabetes, sleep apnea, acid reflux and clinical depression.
That step count is equivalent to walking roughly four miles, depending on the pace.
However, experts who were not involved in the study cautioned against getting too caught up in a magic number of daily steps: If you can be more active, do it.
In fact, the study found that when it came to warding off obesity and certain other health conditions, the more steps the better.
It's a straightforward formula, said Dr. Chip Lavie, medical director of cardiac rehabilitation and prevention at John Ochsner Heart and Vascular Institute in New Orleans.
If the goal is weight control, he said, the more you walk or run, the more calories you burn.
"Generally, we say 100 calories are burned per mile walked or run," said Lavie, who was not involved in the study.
Of course, he noted, if people substantially boost their activity levels, they may eat more. But the "net effect" of being highly active will still translate to weight loss, Lavie said. And that, he added, can cut the risks of heart disease, diabetes and a range of other ills.
Lavie also pointed to a factor that may be just as important as step count: stepping speed, which is key for boosting cardiovascular fitness.
"Fitness," Lavie said, "is one of the strongest protectors against most diseases."
All of that said, the central message of the study is a good one, said Lavie: Get moving, and you may reduce your risk of a host of chronic health conditions.
The study, published Oct. 11 in Nature Medicine, involved just over 6,000 adults aged 41 to 67 who used Fitbit devices to track their daily steps. Researchers at Vanderbilt University Medical Center in Nashville, Tenn., were allowed access to their electronic health records, to see how their daily step counts correlated with their risk of being diagnosed with various chronic ills.
Participants' activity levels were tracked over an average of four years. The median number of daily steps for the group was around 7,700 (roughly 3.5 miles) — which means half took more, and half took fewer.
Over seven years, the study found, people who averaged at least 8,200 steps a day were less likely to develop obesity. They also had lower risks of two conditions often related to obesity: sleep apnea, a nighttime breathing disorder; and acid reflux disease. The odds of being diagnosed with major depression also went down.
But more steps were even better.
People in the top 25% for step count — who typically got close to 11,000 steps per day — were about 30% to 50% less likely to develop those conditions, versus people in the bottom 25%, whose step count hovered around 6,000.
The researchers pointed to a more specific example: If an overweight person increased his or her daily step count from 6,000 to 11,000, that could cut the odds of becoming obese by 64%.
When it came to diabetes and high blood pressure, the study found a "plateau" effect — where the risks of those conditions were reduced when people got between 8,000 and 9,000 steps a day. But moving more did not offer additional protection.
However, Lavie cautioned against reading too much into that finding. "To think that one gets a maximal benefit at 9,000 steps is pretty naive," he said.
Dr. Andrew Freeman is director of cardiovascular prevention and wellness at National Jewish Health in Denver. He agreed that the study does not define a "magic number" of steps for the human body.
"Before cars, people easily walked 10 miles a day," noted Freeman, who had no role in the new research.
Beyond that, exercise is only one ingredient to staying physically and mentally healthy. A diet high in plant foods, adequate sleep and social connection are all critical, too, Freeman said.
This study lacked information on those factors. It also had other limitations, Freeman and Lavie said: People who use a Fitbit are likely health-conscious and motivated, and relatively higher-income. So it's unclear how well these findings might generalize.
Still, the central message — get moving — is sound, both doctors said.
Fitness trackers are not necessary, Freeman said, but if the devices keep you motivated, that's great. He did recommend keeping tabs in some way, such as walking a certain distance or amount of time each day, for the sake of consistency.
The U.S. Centers for Disease Control and Prevention has recommendations on exercise.
SOURCES: Carl "Chip" Lavie, MD, medical director, cardiac rehabilitation and prevention, and director, exercise laboratories, John Ochsner Heart and Vascular Institute, Ochsner Clinical School - The University of Queensland School of Medicine, New Orleans; Andrew Freeman, MD, director, cardiovascular prevention and wellness, and associate professor, National Jewish Health, Denver; Nature Medicine, Oct. 11, 2022