With almost all of us spending a lot of time at home because of the coronavirus pandemic and some under edicts to shelter in place and avoid going out at all, those of us who are used to regular exercise naturally have pressing questions and concerns about how best to stay in shape.
To get answers, I spoke with virologists, physiologists and other scientists about what we do and do not know about exercising during the coronavirus crisis. Here is what they had to say.
If I live in a community that is under a shelter-in-place order, can I run or walk outside?
This answer is easy: yes. The San Francisco County health department’s order, which is likely to be a model for similar announcements, says that people may leave their homes “to engage in outdoor activity, provided the individuals comply with social distancing requirements as defined in this section, such as, by way of example and without limitation, walking, hiking, or running.” So, as long as you remain six feet away from other people (not counting those in your household), you can exercise outside.
Does the sun sterilize surfaces outside?
A trickier question. “It is possible to inactivate viruses using U.V. light in laboratory settings,” says Akiko Iwasaki, a professor of immunology at the Yale University School of Medicine. “However, whether and to what extent natural sunlight kills SARS-CoV2,” the official name of the new coronavirus, “is not yet known.”
So, the safest response is to assume that banisters, benches, pull-up bars, the “walk” buttons on stop lights and other outdoor surfaces might be contaminated and avoid touching them, at least with uncovered skin. Wear gloves (which themselves can become contaminated) or use your elbow to push buttons. “And wash your hands with soap after you return,” Dr. Iwasaki says.
Can I use drinking fountains along my route?
“We don’t have any data about how long the virus remains infectious on water fountains,” says Angela Rasmussen, a virologist with the Center for Infection and Immunity at Columbia University. “But, given their proximity to other people’s mouths and noses, I would say you should not.”
If I am running the prescribed six feet behind someone on the path and they cough, will I jog right through their germs?
The science about how long the novel virus remains in the air is still unsettled. (You can read about a new study of that issue here.) But it is conceivable that droplets containing the virus could linger long enough for you to breathe them in, Dr. Iwasaki says, if you closely follow someone who is ill and the wind does not disperse the germs first. This precise scenario remains unlikely but not impossible, so look for the “least-crowded paths” available, she says, and perhaps swerve aside if someone coughs or spits ahead of you.
Should I take my shoes off before going in the house?
“This is a good rule of thumb,” says Saskia Popescu, a senior infection-prevention epidemiologist at HonorHealth in Arizona. No one knows if the coronavirus sticks to shoes, she says, “but they carry a lot of gunk in general, so leave them at the door.”
How fast am I going to become unfit, if I am stuck inside all day?
The good news is that Wall-E-style slovenliness probably does not await us. But if we abruptly and substantially reduce our workouts, we will experience some amount of physiological detraining, says Charles Pedlar, an associate professor of exercise science at St. Mary’s University in Twickenham, England. In a 2018 study he led, fit runners who voluntarily slashed their mileage after a marathon developed lower blood volume and other changes to their hearts and cardiovascular systems within about two weeks and began to struggle on the treadmill during strenuous running.
Similarly, in another 2018 study, when healthy, young volunteers who normally took about 10,000 steps a day cut back to below 2,000 steps, they began to show heightened blood sugar, lower insulin sensitivity and worse cholesterol profiles within two weeks.
Thankfully, those metabolic consequences receded within the next two weeks, once the young people returned to their normal activities, says Kelly Bowden Davies, a lecturer at Newcastle University, who led the new study. “Increasing daily steps was enough to restore normal health,” she says.
Likewise, Dr. Pedlar says, most of us can expect to recover our former fitness quickly, even if we must temporarily reduce our training. The first few runs or workouts after such a layoff can feel slow and wretched, he admits, “and you may think you’ve lost all of your fitness.” But “don’t panic.” In general, he says, any reductions in blood volume and stamina should soon be regained. “Do not come back too hard,” he advises. Ease into any more-strenuous training regimen once you have additional time and interest. “But know that you can come back.”
OK, so how little exercise can I get away with in the meantime and still stay reasonably fit?
“There is evidence that even about five minutes a day of mini-workouts could be sufficient” to help us maintain a baseline of fitness, says Martin Gibala, a professor of kinesiology at McMaster University in Hamilton, Ontario. And the necessary equipment and instruction for a full-body regimen are minimal.
“Mix push-ups, jumping jacks, burpees, lunges, stair ascents and descents, ideally with short recovery periods to keep heart rate up,” he says. In one of the studies he oversaw recently, young people who hurried up and down flights of stairs for about 20 seconds three times a day increased their aerobic fitness by about 5 percent after six weeks.
So, if you are absolutely housebound, consider enticing your children, dogs and spouse to head up and down the stairs with you a few times or engage in a rousing jumping jack competition. The dogs, I bet, will lose.
Other useful resources:
Many fitness professionals and organizations are offering free online fitness classes and apps of all varieties now. Check YouTube and other social media or your preferred app store to find one that appeals to you.