Jan. 9, 2023 – Jan. 9, 2023 — If you vowed to start exercising this year, here’s another incentive to help you stick to your guns: You could protect yourself from potentially devastating COVID-19 outcomes like hospitalization and even death.
The evidence is piling up that physical activity can lower the risk of getting very sick from COVID. The CDC, based on a systematic review of the evidence, has reported that “physical activity is associated with a decrease in COVID-19 hospitalizations and deaths, while inactivity increases that risk.” Other research has linked regular physical activity with a lower risk of infection, hospitalization, and death from COVID.
The latest such study, from Kaiser Permanente, suggests that exercise in almost any amount can cut the risk of severe or fatal COVID even among high-risk patients like those with high blood pressure or heart disease.
“We found that every level of physical activity provided some level of protection,” says lead study author Deborah Rohm Young, PhD, director of the Division of Behavioral Research for Kaiser’s Southern California Department of Research and Evaluation. “Even a 10-minute walk [per] week is associated with better COVID-19 outcomes.”
The best outcomes were seen among “those who are consistently meeting our national guidelines of greater than 150 minutes a week of at least brisk walking,” she says. That’s 30 minutes of exercise 5 days a week. However, “every bit is beneficial.”
Yet, 1 in 4 adults don’t get any physical activity outside of their jobs, according to the CDC. That matters as we move into January and COVID numbers trend up. As of press time, the CDC is reporting more than 470,000 weekly cases, compared to about 265,000 for the week ending Oct. 12. On average, over 6,000 people were admitted to the hospital per day from Dec. 31 to Jan. 6, and deaths totaled 2,731 weekly as of Jan. 4.
“The missing aspect in our response to the public health challenge of COVID has been the heightened need for personal and community well-health,” says Gene Olinger, PhD, chief science advisor for research company MRIGlobal, and an adjunct associate professor at Boston University School of Medicine. “Proactive medicine – where individuals optimize nutrition, exercise, sleep, and whole-body meditation — is not a priority in the current health ecosystem. It is changing, and this is good news.”
Of course, everyone should still get vaccinated, Young cautions, and not rely on exercise and healthy living alone to ward off severe COVID. “The more we can do to protect ourselves from having bad COVID, it should all be done.”
The More Activity Prior to Infection, the Better
In the Kaiser study, the researchers looked at health records for 194,191 Kaiser adult patients who tested positive for COVID-19 between January 2020 and May 2021.
Patients’ activity levels were assessed using a self-report system that Kaiser has used since 2009 involving two questions: “On average, how many days per week do you engage in moderate to strenuous exercise (like a brisk walk)?” and, “On average, how many minutes do you engage in exercise at this level?” To be included in the study, participants had to have completed at least three of these assessments in the 2 years before infection.
The more active a patient was, the better their outcomes tended to be, the researchers found. Likewise, less active patients saw worse outcomes.
In the most dramatic gap, those who were consistently inactive (less than 10 minutes of activity per week) before getting COVID-19 were 91% more likely to be hospitalized, and 291% more likely to die from the disease, than active patients.
Like all studies, this one had limitations. Because it took place before vaccinations were easier to get, it could not assess whether physical activity improved outcomes among the vaccinated. It also did not look at exercise’s impact on those with repeat COVID-19 infections. Still, the study suggests that inactive folks should boost their activity to help ward off severe COVID-19.
The exercise benefits come as no surprise to physician Kwadwo Kyeremanteng, MD, head of critical care at the Ottawa Hospital, in Canada, and an associate professor at the University of Ottawa.
“As an ICU physician who has been taking care of COVID patients from day one, I saw on a regular basis that people in poor metabolic health had bad outcomes,” says Kyeremanteng, who was not involved in the study. “It was clear early on [that] obesity, diabetes, and metabolic disease [were] risk factors for severe COVID and dying from COVID. Basically, the results of the study correlate with what we saw on the front lines.”
Fitness Is No Guarantee
It’s important to note that all trends have outliers. Even highly conditioned athletes who exercise often and hard can — and do — become very ill with COVID and can have lingering symptoms like shortness of breath, severe fatigue, and brain fog.
“In younger athletes and those who are optimally fit, there is evidence that COVID can cause myocardial inflammation [heart damage] in one out of 100,” says Olinger. “Fortunately, it is almost always reversible.”
And while controversial, the concept of over-exercising (aka overtraining syndrome) has been associated with suppressed immune function and more cases of upper respiratory tract infection, he says.
“However, the level of exercise that one can achieve varies widely,” Olinger says. “The data is clear that vaccinations for COVID and regular exercise are key to a lifelong resistance to disease and infections.”
What About Exercising After You Get COVID?
Another caution: While the evidence shows that exercise before getting COVID-19 can help improve outcomes, other research has found that returning to exercise too soon after contracting the virus can be dangerous, regardless of your fitness level. In fact, exercise is likely to make long COVID symptoms worse.
After a bout with COVID-19, return to exercise gradually, says Kyeremanteng. Let your symptoms be your guide. A study in the Journal of Science and Medicine in Sport suggests that athletes with no or minimal symptoms should return to their pre-COVID exercise habits in a “graduated fashion” over 7 to 14 days. “Those with pre-existing medical comorbidities should adopt a more cautious approach,” the study says.
“Listen to your body,” says Olinger. “You are the only one who knows what feels right.”