Exercise in COVID-19: Intensity and Timing


Mostafa Mohammadi 1 , Mohammad Reza Hadian ORCID 2 , Hesam Aldin Varpaei ORCID 3 , *

1 Department of Anesthesiology and Critical Care, Department of Spiritual Health, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran

2 School of Rehabilitation, Institute of Neuroscience, Tehran University of Medical Sciences, Tehran, Iran

3 Department of Medicine, McGill University, Montreal, Canada

How to Cite: Mohammadi M , Hadian M R, Varpaei H A. Exercise in COVID-19: Intensity and Timing, Asian J Sports Med. Online ahead of Print ; In Press(In Press):e113266. doi: 10.5812/asjsm.113266.


Asian Journal of Sports Medicine: In Press (In Press); e113266
Published Online: May 19, 2021
Article Type: Letter
Received: January 27, 2021
Accepted: February 16, 2021
Uncorrected Proof scheduled for 12 (3)

Dear editor,

COVID-19 outbreak around the world raises concerns about patient management, particularly in the critical care setting (1, 2). Conventionally, bed rest had been suggested for patients following flu-like syndromes, and therefore, this concept could be applied for covid-19 infection. Accordingly, one might have hypothesized that bed rest could be beneficial for COVID-19 patients, particularly in the acute phase. Our experiences at the bedside showed some findings in this regard because we observed that the patient's condition had deteriorated and oxygenation level decreased soon after moderate activity. In the symptomatic phase, the patients might take advantage of short periods of bed rest. It seems that exercise would have mental and physical advantages for patients in the first days of infection (3). Also, Pieces of evidence about COVID-19 home confinement suggested that low/medium intensity high volume exercise, and decreasing the calorie intake by 15 to 25 percent could prevent the harmful consequences of sedentarism (4). In terms of cellular and molecular, Moderate exercise in the early stages of infection can reduce pulmonary cellular infiltration and a shift from a T-helper 1 to a T-helper 2 index (5, 6). Reducing symptoms, inflammatory factors, virus load, and inflammatory cytokine level is associated with persistent exercise. Then, acute exercise could be beneficial, which is limited to the primary phase of infection. Consequently, it could reduce the viral load, mitigate cytokine storm, shorten the sectional acute phase, and accelerate recovery (7). However, there are no randomized controlled trials in the field of COVID-19; and then, more studies are required. Also, mild exercise could improve the autophagy mechanism (8) which ameliorates the function of the immune system in response to COVID-19 infection.

It is hypothesized that COVID-9 patients might represent two phenotypes as follow (9): Type L (Low elastance i.e. high compliance, ventilation-to-perfusion ratio, lung weight, and recruitability), and Type H (High elastance, right-to-left shunt, lung weight, and recruitability). At the first stage, COVID-19 pneumonia demonstrates L type phenotype; these patients might stay without any changes for some time and later on could improve or exacerbate. Over time, as shortness of breath develops, a transition from L type to H type occurs due to high-stress ventilation. In high elastance, low tidal volume is required for ventilation, and therefore, high tidal volume and respiratory effort seem to be deleterious and hazardous. In the inflammatory phase specifically in H-type patients (COVID-19) intensive deep breathing could cause pulmonary epithelial injury. Accordingly, for hospitalized patients, especially in the intensive care unit, respiratory physiotherapy is requested. In the case of pulmonary involvement (ARDS), all efforts should be focused to reduce trans-pulmonary pressure, pulmonary edema, and, probable lung injury. Therefore, a low tidal volume strategy is performed in mechanically ventilated patients with low compliance in order to prevent shear stress. In the inflammatory phase of the disease, it seems that high tidal volume and high transpulmonary pressure could be injurious; therefore, it might be the case in spontaneous breathing. Perhaps forcing the patient to take deep breaths (Similar to what happens in sports) or provoking a severe cough in the inflammatory phase may increase the damage. Therefore, at this stage, it is better for the patient to be more relaxed, and to compensate for this immobility, an anticoagulant should be prescribed (10) to the patients under the guidance of a d-dimmer (prophylactic, mild dose, or moderate dose).

Bearing in mind, at the inflammatory phase, intensive exercise, and particularly without the supervision of an expert physical therapist is not beneficial at all and even could be considered as a second hit phenomenon. Mild exercises in bed rest period (i.e., acute phase) could prevent the probability of coagulation in pulmonary capillaries and deep vein thrombosis (11). It might lead to health promotion in COVID-19 infected patients.



  • 1.

    Varpaei HA. Investigating the relationship between clinical characteristics of 2019 novel coronavirus pneumonia cases (covid-19) before intubation and treatment outcome after 14 days in Imam Khomeini hospital complex, Tehran, Iran: Descriptive-analytic study. Am J Biomed Sci. 2020;10(6):478-89. doi: 10.34297/AJBSR.2020.10.001556.

  • 2.

    Bikdeli B, Talasaz AH, Rashidi F, Sharif-Kashani B, Farrokhpour M, Bakhshandeh H, et al. Intermediate versus standard-dose prophylactic anticoagulation and statin therapy versus placebo in critically-ill patients with COVID-19: Rationale and design of the INSPIRATION/INSPIRATION-S studies. Thromb Res. 2020;196:382-94. doi: 10.1016/j.thromres.2020.09.027. [PubMed: 32992075]. [PubMed Central: PMC7513771].

  • 3.

    Halabchi F, Ahmadinejad Z, Selk-Ghaffari M. COVID-19 epidemic: Exercise or not to exercise; That is the question!. Asian Journal of Sports Medicine. 2020;11(1). doi: 10.5812/asjsm.102630.

  • 4.

    Narici M, De Vito G, Franchi M, Paoli A, Moro T, Marcolin G, et al. Impact of sedentarism due to the COVID-19 home confinement on neuromuscular, cardiovascular and metabolic health: Physiological and pathophysiological implications and recommendations for physical and nutritional countermeasures. Eur J Sport Sci. 2020:1-22. doi: 10.1080/17461391.2020.1761076. [PubMed: 32394816].

  • 5.

    Sim YJ, Yu S, Yoon KJ, Loiacono CM, Kohut ML. Chronic exercise reduces illness severity, decreases viral load, and results in greater anti-inflammatory effects than acute exercise during influenza infection. J Infect Dis. 2009;200(9):1434-42. doi: 10.1086/606014. [PubMed: 19811098]. [PubMed Central: PMC2812897].

  • 6.

    Lowder T, Padgett DA, Woods JA. Moderate exercise early after influenza virus infection reduces the Th1 inflammatory response in lungs of mice. Exerc Immunol Rev. 2006;12:97-111. [PubMed: 17201075].

  • 7.

    Martin SA, Pence BD, Woods JA. Exercise and respiratory tract viral infections. Exerc Sport Sci Rev. 2009;37(4):157-64. doi: 10.1097/JES.0b013e3181b7b57b. [PubMed: 19955864]. [PubMed Central: PMC2803113].

  • 8.

    Wang L, Wang J, Cretoiu D, Li G, Xiao J. Exercise-mediated regulation of autophagy in the cardiovascular system. J Sport Health Sci. 2020;9(3):203-10. doi: 10.1016/j.jshs.2019.10.001. [PubMed: 32444145]. [PubMed Central: PMC7242217].

  • 9.

    Gattinoni L, Chiumello D, Caironi P, Busana M, Romitti F, Brazzi L, et al. COVID-19 pneumonia: different respiratory treatments for different phenotypes? Intensive Care Med. 2020;46(6):1099-102. doi: 10.1007/s00134-020-06033-2. [PubMed: 32291463]. [PubMed Central: PMC7154064].

  • 10.

    Barnes GD, Burnett A, Allen A, Blumenstein M, Clark NP, Cuker A, et al. Thromboembolism and anticoagulant therapy during the COVID-19 pandemic: interim clinical guidance from the anticoagulation forum. J Thromb Thrombolysis. 2020;50(1):72-81. doi: 10.1007/s11239-020-02138-z. [PubMed: 32440883]. [PubMed Central: PMC7241581].

  • 11.

    Kollias A, Kyriakoulis KG, Dimakakos E, Poulakou G, Stergiou GS, Syrigos K. Thromboembolic risk and anticoagulant therapy in COVID-19 patients: emerging evidence and call for action. Br J Haematol. 2020;189(5):846-7. doi: 10.1111/bjh.16727. [PubMed: 32304577]. [PubMed Central: PMC7264537].

  • Copyright © 2021, Author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/) which permits copy and redistribute the material just in noncommercial usages, provided the original work is properly cited.