The relationship between inactivity and the severity of covid-19 symptoms

An area from the 90’s that is receiving much attention from researchers is Exercise Immunology.

Thanks to this branch of science, we all know the importance of exercise for our health and to prevent certain comorbidities such as cardiovascular disease. Exercise not only has direct/acute impact in our immunity as well as chronic effects. The benefits that we get from exercise will depend on the frequency and intensity of our activity.

According to the World Health Organization there are guidelines for exercise that one should meet depending on age:

  • 5 to 18 years of age – Moderate to intense physical activity, 60 minutes per day, on average.
  • 19 – 64 years of age – Minimum of 150 minutes per week of moderate intensity or 75 min per week of high intensity training.
  • Over 64 years of age – 150 minutes of moderate aerobic exercise and build up their level to shorter intervals of higher intensity.

But to what extent can exercise help us to prevent serious illness with Covid-19 infection?

After two years of pandemic, it is now, well known that, advanced age or previous organ transplant are the main risk factors for having severe Covid-19 disease. However recent research has demonstrated that the lack of physical activity, or not meeting the guidelines for the appropriate amount of physical activity in our age can lead to severe symptoms after Coronavirus infection.

Reduced levels of activity only come in third place, after age and organ transplants on the list of factors that contribute to severe disease/symptoms. This is followed by gender and certain medical conditions such as respiratory problems or diabetes.

A recent study by Sallis, et al. evaluated the effects of physical activity (performed during the two years that preceded the infection by coronavirus) on 48.440 individuals, important to note that these individuals were as well distinguished by gender, age, BMI and comorbidities; – Each individual reported three times their levels of activity over the two years, and they were separate in three different groups:

  • Inactive – 0-10 min of activity/week – In this group were 15 % of the individuals
  • Moderately activity – 11-149 min of activity/ week – this groups constitutes of 78% of the individuals
  • Meets activity guidelines – 150 + min / week and this group accounts for 7% of the individuals

The results of this study is consistent with what we can currently find in literature about exercise and it’s effect on our health and it showed that patients that were inactive were more than twice as likely to be admitted to hospital; 73% of these patients were more likely to need intensive care and 2.5 times more likely to die from Covid-19 infection.

This suggests that increasing the amount of physical activity, weekly, may be the best prevention we have for covid-19 infection along with a use of masks and vaccines.


1 – Nieman, D. C., & Wentz, L. M. (2019). The compelling link between physical activity and the body’s defense system. Journal of sport and health science, 8(3), 201–217.

2 – Sallis, R., Young, D. R., Tartof, S. Y., Sallis, J. F., Sall, J., Li, Q., Smith, G. N., & Cohen, D. A. (2021). Physical inactivity is associated with a higher risk for severe COVID-19 outcomes: a study in 48 440 adult patients. British journal of sports medicine, 55(19), 1099–1105.

3 – Bull FC, Al-Ansari SS, Biddle S, Borodulin K, Buman MP, Cardon G, Carty C, Chaput JP, Chastin S, Chou R, Dempsey PC, DiPietro L, Ekelund U, Firth J, Friedenreich CM, Garcia L, Gichu M, Jago R, Katzmarzyk PT, Lambert E, Leitzmann M, Milton K, Ortega FB, Ranasinghe C, Stamatakis E, Tiedemann A, Troiano RP, van der Ploeg HP, Wari V, Willumsen JF. World Health Organization 2020 guidelines on physical activity and sedentary behaviour. Br J Sports Med. 2020 Dec;54(24):1451-1462. doi: 10.1136/bjsports-2020-102955. PMID: 33239350; PMCID: PMC7719906.