College students may reverse the effects of inactivity within a day or two, but it’s a different story for adults who drop their active lifestyle. Two new studies show that just a few weeks of inactivity could leave us less healthy, and the effects could last for a prolonged period. Increasing age could magnify the consequences. Even if an injury or hospitalization slows you down, keep up your regular exercise and physical activity, advises Chris McGlory, a Canadian researcher who led one study.
“It’s not uncommon for older people to become sick or injured and wind up hospitalized or housebound for several weeks, or for someone who’s younger to just decide to take a few weeks off,” he says. But “if it’s at all possible,” he says, “don’t stop moving.” He recommends talking to a physical therapist about activity options.
Here’s why cutting back on physical activity can set your health back, according to the two new studies. The first study asked 45 adult women and men to reduce their normal routine of walking more than 10,000 steps on most days. They cut back to fewer than 2,000 steps and they increased sitting for more than three and a half additional hours each day.
The volunteers continued this routine for two weeks, and at the end of that period their blood sugar levels had climbed, and their cholesterol profiles were less healthy. They had added fat around their abdomens and lost a little muscle mass in their legs. Their insulin sensitivity declined.
Most of these impacts reversed when the women and men and women resumed active exercise. However, a few of the volunteers did not return to their previous level of exercise. They engaged in less vigorous exercise each week than previously. Two weeks after resuming their normal activity, they showed some slight but lasting symptoms of insulin resistance.
The second study focused on overweight people past age 65 who were healthy and walking about 7,000 to 8,000 steps each day. Their high blood sugar levels, however, put them at risk of developing diabetes. Researchers asked them to cut back walking to fewer than 1,000 steps a day for two weeks before returning to their normal activity in the last week weeks of the study.
In this study the ill effects that developed did not fully reverse after two weeks of moving again. Those harmful results included worse blood sugar control and climbing insulin resistance. Some showed indications that they might soon start losing muscle mass. A few who edged into full-blown Type 2 diabetes had to leave the study.
The first of these new studies was published in June in Diabetologia and conducted by researchers at the University of Liverpool in England. The second study conducted by researchers at McMaster University in Canada was published in July in The Journals of Gerontology.

Read more: Take a Vacation from Exercise? Your Body May Not Thank You