Listen to your body. It's the age-old advice for people deciding if they they can exercise when they're under the weather. Feeling relatively decent or just slightly blah? Going for a jog or bike ride could invigorate you. Seriously dragging? Better take a rest day to let your body recoup, and maybe you can return to your regularly scheduled workouts the next day.
With COVID-19, you might need to play things a little more cautious. "Exercising with COVID-19 is very different than exercising through a cold, which you may have done in the past," says Jordan Metzl, MD, a sports medicine physician at the Hospital for Special Surgery (HSS) in New York City.
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That doesn't mean you can't and shouldn't stay active during COVID to keep your muscles and lungs as healthy as possible. But August 2020 guidelines from the HSS urge everyone who has tested positive for COVID-19 to avoid working out (especially at a high intensity) until they've had at least seven days without symptoms. This timeframe is much longer for people who experience heart-related complications of COVID-19.
Here, experts explain why you should only do gentle exercise with COVID-19. Plus, when it's safe to get back after it.
Get tips on how to stay healthy, safe and sane during the novel coronavirus pandemic.
4 Reasons to Avoid Intense Exercise During COVID
Working out could worsen the disease, but it can also lead to rare but life-threatening complications.
1. It May Stress Your Heart
Scientists are exploring the risk of heart issues linked to COVID-19. Right now, it seems that the most common heart-related complication is acute cardiac injury, according to a February 2021 analysis from the American College of Cardiology (ACC).
"Acute cardiac injury" is a vague term. It applies whenever the heart releases large amounts of a protein called troponin, which points to heart-muscle damage. About 22 percent of people in intensive care units (ICUs) for COVID-19 have acute cardiac injury, according to the ACC. In rare cases, too-high troponin levels may signal myocarditis, an inflammation of the heart muscle, per one January 2021 Journal of the American College of Cardiology study.
When the heart is already over-stressed, it's possible that exercise could add to the problem, says physical therapist Sharlynn Tuohy, DPT, co-author of the HSS Beyond COVID-19 rehabilitation exercise program. Plus, the more you exert yourself, the more oxygen your muscles and tissues need to keep up. That's a problem when you're having trouble breathing deeply.
By the way, it's not only seriously sick people who have heart issues with COVID. In a July 2020 JAMA Cardiology study of 100 people who had recently recovered from the disease, 78 percent had heart-related symptoms — despite the fact that many of them had no pre-existing conditions and were not hospitalized. A September 2020 study in JAMA Cardiology found signs of myocarditis in student athletes who had mild or no symptoms.
2. It Could Dislodge a Blood Clot
COVID-19 increases your likelihood of blood clots. According to an August 2020 study in the American Journal of Hematology, this is because severe infections can raise the levels of a blood-clotting protein in the body.
Although exercise can lower your risk of developing blood clots in the first place, it can be dangerous to work out once one has already formed. "The clot could then travel to your lungs," Tuohy says, which can be fatal.
3. It Can Weaken Your Immune Defenses
During COVID, you need to conserve your resources. Fighting off an infection that's as severe as COVID-19 is hard work for your body, which is why so many people experience fatigue. You need to channel your energy toward slaying the virus, not tearing it up on your treadmill.
Still, even if you've got zero symptoms, put high-intensity exercise on hiatus. "I recommend against HIIT while you have an active infection," says Rachel Volkl, PT, DPT, a physical therapist at Rush University Medical Center in Chicago. "High-intensity exercise — or heavy exercise outside of what your body is accustomed to — can blunt your immune system response. That may negatively affect your body's ability to fight off an infection and prolong your time to recovery."
4. It May Increase Inflammation
While rare, 4 percent of people with COVID-19 experience a cytokine storm (an over-response of the immune system that creates systemic inflammation, causing the body to attack normal, healthy cells), according to a December 2020 study in Science Advances.
"Exercise typically has anti-inflammatory effects, but if you are in a state of acute inflammation, it might actually set you way back," Tuohy says.
Stick With Light Exercise During COVID
Experts agree that you need to avoid high-intensity exercise during COVID-19. But very gentle forms of exercise, let's call it "activity" or "movement," may help you recover.
"Light movement will help minimize any potential strength and muscle loss that can accompany COVID-19 infection," Volkl says. "It reduces the likelihood of developing blood clots. It protects your heart health and keeps the lungs more active than if you were to stick with strict bedrest."
"We know that, in general, those who become very sedentary or bedridden from an illness or adverse health event — COVID-19-related or not — can experience a significant decline in function which then can contribute to further decline in health, making them susceptible to chronic conditions and illnesses," Volkl says.
According to Rush University Medical Center, people who are asymptomatic have the green light to do low-intensity exercise as long as they monitor how they feel.
"Take our critically ill patients with COVID in the ICU or on step-down units: Most of these individuals receive physical therapy regularly in order to minimize the extent of these complications," Volkl says. "Why would we discourage people who are at home, feeling well, to be sedentary?"
Meanwhile, if your symptoms are mild or moderate, you can stay moving with very light activities. We're talking basic things like walking around the house, taking a shower, getting dressed or making a cup of tea.
Really feeling crappy? Try to get up to walk laps in your hallway or change positions in bed. (Anyone with severe symptoms should talk to their doctor about what activities they should and shouldn't keep up.)
The goal is to move, even just a little, every hour, according to Volk.
Keep tabs on how you feel and let your doctor know if you have any new symptoms, such as shortness of breath or coughing, Volkl says. And during infection, all exercise should be in quarantine. Do not work out around others while you're contagious.
According to the Centers for Disease Control and Prevention, you should quarantine for at least 10 days after a positive test result.
Can You Exercise With COVID?
Volkl recommends using the "neck check" to figure out.
It's OK to exercise if your symptoms are above the neck, like with:
- Nasal congestion
- Sore throat
- Runny nose
You should hold off on exercise if your symptoms are below the neck, like with:
- Chest congestion
- Persistent coughing
Read more stories to help you navigate the novel coronavirus pandemic:
- Science Advances: "Distinct inflammatory profiles distinguish COVID-19 from influenza with limited contributions from cytokine storm"
- CDC: "When You Can be Around Others After You Had or Likely Had COVID-19"
- HSS: "HSS Experts Release Evidence-Based Guidelines for Returning to Recreational Exercise After COVID-19"
- Journal of the American College of Cardiology: "High Prevalence of Pericardial Involvement in College Student Athletes Recovering From COVID-19"
- HSS: "Exercise and COVID-19 Can Be a Dangerous Combination, Evidence Shows"
- JAMA Cardiology: "Outcomes of Cardiovascular Magnetic Resonance Imaging in Patients Recently Recovered From Coronavirus Disease 2019 (COVID-19)"
- JAMA Cardiology: "Cardiovascular Magnetic Resonance Findings in Competitive Athletes Recovering From COVID-19 Infection"
- ACC: "COVID-19 as a Possible Cause of Myocarditis and Pericarditis"
- Journal of the American College of Cardiology: "Pathological Evidence for SARS-CoV-2 as a Cause of Myocarditis: JACC Review Topic of the Week"