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On the couch the past three months? Here’s how this sedentary period may have affected your health

Fitness instructor Christie Wang leads a virtual pilates class with students on a Zoom call in her Cambridge apartment. She saw some clients stop exercising during the first couple of months of the shutdown as schools closed and routines were upended.Matthew J. Lee/Globe staff

Beth Whitney can tell she’s not as strong physically as she was before the COVID-19 shutdown.

That’s saying something. Whitney co-owns and manages a gym in Milton called Fitness Unlimited, and she’s taught fitness classes for years. But she found that exercising by herself wasn’t the same.

“Being with other people, for me, it just pushes me harder,” she said. Virtual classes helped, but when it came to strength training, she couldn’t get motivated. “It’s just weird. I tried. I really have no excuse, I work at a gym.”

Whitney’s may be the best-case scenario. A great many Americans have not left the couch much at all in recent months as stay-at-home orders, job losses, and chronic stress have taken a toll on physical and emotional well-being. While essential employees continued to make their way to work, others hunkered down, minimizing even incidental activity.


Just what impact this period has had on an individual’s physical health depends on a variety of factors, experts say, including a person’s age and fitness levels before the shutdown began. But the effects of “detraining,” or what happens to the body when a person stops exercising, are measurable, especially when it stretches on for weeks or more at a time.

“It’s not something that happens instantaneously,” Meagan Murphy Wasfy, a sports cardiologist at Massachusetts General Hospital, said of the effects of detraining. “But two and a half months is definitely in the wheelhouse of when you can see measurable declines.”

Though Massachusetts has entered Phase 2 of reopening, life is far from normal. Gyms remain closed, as do schools. Many people continue to work from home, with no time or space for exercise.

“I’ve been working 18 hour days since I closed my office,” Marlo Fogelman said of her Back Bay firm, Marlo Marketing. As she scrambled to help her clients and employees, exercise dropped off the priority list. “So I am trying to be kind to myself, and recognize that there is only so much I can do at one time, and I’m consciously letting the gym go.”


Experts say the effects of detraining can be especially acute for older people and those who were only moderately active before the shutdown. The younger you are, the more physically resilient you tend to be. But someone in their 50s or 60s will not only see a quicker fitness decline, it will take longer to get it back.

“The rate at which you atrophy is much greater as you age,” said Dustin Allen, PhD, a lecturer at Boston University’s College of Health and Rehabilitation Sciences. “But any time you engage in a sedentary lifestyle, you see declines in muscle function, regardless of age.”

One of the first signs of fitness loss can be seen in the level of oxygen uptake — that is, how much oxygen can be consumed and delivered throughout the body — during intense exercise. That rate of oxygen consumption, known as VO2 max, is particularly responsive to detraining. When people are exercising regularly, the heart strengthens and enlarges, pumping a greater volume of blood throughout the body. Once exercise stops, the volume of blood — and the oxygen it carries — decreases.

“The heart has to work harder to achieve the same amount of blood flow,” Allen said. Over time, the numbers of capillaries surrounding muscles begin to decline, and reductions in mitochondria, the powerhouses of cells, make cells less able to produce energy. People who are pre-diabetic or diabetic will also see greater swings in blood sugar levels.


Unlike elite athletes or highly active individuals who don’t see the effects of detraining for quite some time, more sedentary populations can quickly see the loss of “working range” fitness, or the ability to perform basic activities without becoming winded or fatigued.

That includes a lot of us. Even during the best of times, when gyms are open and pick-up basketball games don’t require a second thought, Americans aren’t exactly paragons of fitness. Only 23 percent of Americans ages 18-64 meet recommended guidelines for physical activity, according to a 2018 National Health Statistics report from the CDC. Obesity rates keep climbing. A 2019 study from Harvard’s T.H. Chan School of Public Health predicts that by 2030, nearly half of Americans will suffer from obesity.

Allen often uses the Dallas Bed Rest Study from 1966 to make clear how big an impact sedentary behavior can have on health. In the initial study, a handful of male subjects remained on bed rest for three weeks, before and after which their fitness was measured. What researchers found, in part, was that three weeks of “being completely sedentary ... decreased cardiovascular fitness more than aging 30 years,” Allen said in an email.

“It isn’t a perfect study,” he cautioned, “but I use it as an attention grabber in my exercise physiology classes to emphasize how important exercise is.”


Disruptions to physical activity are, of course, only one part of the equation. A new survey from the Johns Hopkins Bloomberg School of Public Health says the percentage of adults reporting psychological distress has risen from 3.9 percent in 2018 to 13.6 percent in April 2020. The increases were especially acute among young people 18-29, households with incomes of less than $35,000, and Hispanic adults. Recent Census data indicates that levels of anxiety and depression have soared across the board, with Black Americans, already disproportionately impacted by the pandemic, seeing a sharp increase after the death of George Floyd.

“We need to prepare for higher rates of mental illness among U.S. adults post-COVID,” Beth McGinty, associate professor in the Bloomberg School’s Department of Health Policy and Management, said in a statement.

But as we cast a wary eye toward the future, many of us will need to acknowledge just how arduous this year has been.

“We didn’t have a playbook for the last few months," said Boston-based fitness instructor Ashley Mitchell. “There was no way to prepare our bodies, and no way to prepare our minds.” Going forward “it’s not only about rebuilding the physical body but mentally as well.”

Hayley Kaufman can be reached at hayley.kaufman@globe.com. Follow her on Twitter @GlobeHayleyK.