Originally Published: 20 MAR 23 11:00 ET

Updated: 20 MAR 23 11:46 ET

By Sandee LaMotte, CNN

(CNN) -- Americans took fewer steps during the height of the Covid-19 pandemic, and they still haven't gotten their mojo back, a new study found.

"On average, people are taking about 600 fewer steps per day than before the pandemic began," said study author Dr. Evan Brittain, associate professor of cardiovascular medicine at Vanderbilt University Medical Center in Nashville.

"To me, the main message is really a public health message — raising awareness that Covid-19 appears to have had a lasting impact on people's behavioral choices when it comes to activity," he said.

Who walked the least

The study used data from the National Institutes of Health's All of Us Research Program, which is focused on identifying ways to develop individualized health care. Many of the 6,000 participants in the program wore activity trackers for at least 10 hours a day over multiple years and allowed researchers access to their electronic health records.

Brittain and his colleagues have used the ensuing data before, publishing a study in October 2022 that found overweight people could lower their risk of obesity by 64% by increasing their steps taken from about 6,000 to 11,000 per day.

In the new study, published Monday in JAMA Network Open, researchers compared steps taken by nearly 5,500 people who wore the program's activity trackers. Most were White women, with an average age of 53.

Step counts collected between January 1, 2018, and January 31, 2020, were considered pre-Covid. Steps tracked after that date until the end of 2021, which is when the study ended, were considered post-Covid.

Results showed no difference in identified step activity based on sex, obesity, diabetes and other illnesses or conditions such as coronary artery disease, hypertension or cancer.

People who took the fewest steps were socioeconomically disadvantaged, under psychological stress and not vaccinated, the study said.

Age made a difference as well, but in an unexpected manner: People over 60 were not impacted by the pandemic, the study found — they continued to keep their steps up.

Oddly, it was younger people between 18 and 30 whose step counts were most impacted, Brittain said. "In fact, we found every 10-year decrease in age was associated with a 243 step reduction per day."

"If this persists over time, it could certainly raise the risk of cardiovascular disease, obesity, hypertension, diabetes and other conditions strongly linked to being sedentary," Brittian said. "However, it's too soon to know whether this trend will last."

Younger generations more at risk?

Why would a younger generations lose steps while older people did not?

"I think it's difficult to interpret because it's only 600 steps, which you could argue is what some people would get simply walking into work and through their day," said Dr. Andrew Freeman, director of cardiovascular prevention and wellness at National Jewish Health, a hospital in Denver, who was not involved in the research. "I think the question is who is more likely to work from home?"

Younger generations make up the majority of workers in technology, software and other professions that are able to work from anywhere, "whereas older people may have less of those jobs," Freeman said.

Whatever the reason, the study data shows that people were not moving as much during the pandemic as they used to. That is worrisome, Freeman added.

"If this trend remains, we should really be cognizant that if you're going to work from home, use either a standing, treadmill or bike desk," he said, adding that managers of remote employees should "insist people take periodic breaks for people to do exercise, which also is proven to improve mental clarity and acuity," he said.

Health professionals should always be talking to their patients about activity levels, but "the impact of Covid-19 might make those kinds of messages all the more important to discuss with patients," Brittain said.