Summary Aim To quantify the association between physical activity and the risk of SARS-CoV-2 infection, COVID-19-associated hospitalization, severe illness, and death from COVID-19 in adults. Design A systematic review and meta-analysis. Data sources Three databases were systematically searched up to March 2022. Eligibility criteria for selecting studies Peer-reviewed articles that reported the association between regular physical activity and at least one COVID-19 outcome in adults were included. Risk estimates (OR, relative risk ratios [RR], or HR) were extracted and pooled using a random effects inverse variance model. Results Sixteen studies were included (n=1,853,610). In general, those who performed regular physical activity had a lower risk of infection (RR=0.89; 95% CI 0.84 to 0.95; I2=0%), hospitalization (RR=0.64; 95% CI 0.54 to 0.76; I2=48.01%), severe illness from COVID-19 (RR=0.66; 95% CI 0.58 to 0.77; I2=50.93%) and death related to COVID-19 (RR=0.57; 95% CI 0.46 to 0.71; I2=26.63%) compared to their inactive peers. Results indicated a nonlinear dose-response relationship between physical activity presented in metabolic equivalent of task (MET)-min per week and severe illness and death from COVID-19 (p for nonlinearity <0.001) with dose flattening –response curve around 500 MET-min per week. Conclusions Regular physical activity appears to be linked to a lower likelihood of adverse COVID-19 outcomes. Our findings highlight the protective effects of engaging in sufficient physical activity as a public health strategy, with potential benefits in reducing the risk of severe COVID-19. Given the heterogeneity and risk of publication bias, additional studies with standardized methodology and reporting of results are now needed. |
What is already known about the topic
- Regular physical activity has a protective effect against the severity of respiratory infections.
- Regular physical activity is associated with a multitude of beneficial health effects, including reducing the incidence of risk factors for adverse COVID-19 outcomes (i.e., obesity, type 2 diabetes).
What does this study contribute?
- Regular physical activity is associated with a lower risk of SARS-CoV-2 infection and a lower likelihood of adverse COVID-19 outcomes (including hospitalization, severity, and mortality), although due to study limitations, Our findings should be interpreted with caution.
- The greatest benefit is obtained by achieving at least 500 metabolic equivalents of task (MET)-min per week of physical activity, which is equivalent to 150 min of moderate-intensity physical activity or 75 min of vigorous-intensity physical activity per week.
How it affects clinical practice and public health
- These findings may help guide clinicians and healthcare policy makers to make recommendations and develop guidelines regarding the degree of physical activity that can help reduce the risk of adverse COVID-19 outcomes both at the individual and population, especially in high-risk patients. .
Comments
Regular physical activity is linked to a lower risk of COVID-19 infection and severity, including hospitalization and death, according to a pooled data analysis of available evidence published in the British Journal of Sports Medicine .
A weekly count of 150 minutes of moderate-intensity physical activity, or 75 minutes of vigorous intensity, appears to provide the best protection, the analysis suggests.
Previous research suggests that physical activity may decrease both the risk of infection and the severity of respiratory infections due, at least in part, to its ability to boost the immune system.
The link between regular physical activity and the severity of COVID-19 is not well understood, but likely involves both metabolic and environmental factors, say the researchers, who set out to try to quantify the threshold of physical activity that might be necessary to reduce the risks of infection. and associated hospitalization and death.
They searched 3 major research databases for relevant studies published between November 2019 and March 2022, and from an initial search of 291, they grouped the results of 16. The studies included a total of 1,853,610 adults, of which few more than half (54%) were women. The average age of the participants was 53 years. Most of the studies were observational and were carried out in South Korea, England, Iran, Canada, the United Kingdom, Spain, Brazil, Palestine, South Africa, and Sweden.
Analysis of pooled data showed that, overall, those who included regular physical activity in their weekly routine had an 11% lower risk of infection with SARS-CoV-2, the virus responsible for COVID-19.
They also had a 36% lower risk of hospital admission, a 44% lower risk of severe illness from COVID-19, and a 43% lower risk of death from COVID-19 than their physically inactive peers.
The maximum protective effect occurred around 500 minutes per week of metabolic equivalent of task (MET), after which there was no further improvement.
The METS express the amount of energy (calories) expended per minute of physical activity, and 500 of them are equivalent to 150 minutes of moderate-intensity physical activity or 75 minutes of vigorous-intensity physical activity.
The researchers caution that the analysis included observational studies, different study designs, subjective assessments of physical activity levels, and referred only to the Beta and Delta variants of SARS-CoV-2 rather than Omicron, all of which may weaken the findings.
But there are plausible biological explanations for what they found, they say. Regular moderate-intensity exercise may help boost the body’s anti-inflammatory responses , as well as cardiorespiratory and muscular fitness, all of which may explain its beneficial effects on the severity of COVID-19, they suggest.
They conclude : “Our findings highlight the protective effects of engaging in sufficient physical activity as a public health strategy, with potential benefits in reducing the risk of severe COVID-19. "Given the heterogeneity and risk of publication bias, more studies with standardized methodology and reporting of results are now needed."
