The Role of Exercise and Physical Activity against COVID-19: A Narrative Review Study
Authors: Heidari Diako , Mehdipour Aref 
Published: September 2021

The aim of this study was to understand the role of sport on covid-19 through reviewing the published literature. This was a narrative review that used valid keywords for searching the related scholarly articles. The search for the related keywords on Pubmed, Scopus, Science Direct library and Google Scholar lead to 1158 articles in 2020. After screening 28 article found eligibility to be inclouded in the review. The result indicated that physical activity and exercise play a role in preventing novel coronavirous infection and strengthening the immune system againt the covid-19. Extended Abstract Background and Objectives Since COVID-19 virus is an unknown virus which has caused alarming death toll over the past year, researchers felt implelled to take measures through doing extensive research studies in a variety of related fields to control the virus. On the other hand, exercise is known as a useful non-pharmacological method to improve the function of the immune system, so researchers in the field of sports science have done valuable research studies in this research domain, albeit limited, which can provide us with valuable information in this regard. Hence, there is a pressing need to collect and categorize these latest findings. Therefore, the very aim of this study was to review literature on the role of exercise and physical activity against the COVID-19. Material and Methods This was a narrative review, the data was collected through searching and reteriving available articles published in information resources like Medline (PubMed), Scopus , Science Direct collection, and also Google Scholar. The keywords employed for search strategy building included: "Exercise Training", "Physical Activity", "Aerobic Exercise", "Interval Training", "Resistance Training", "Endurance Training", "COVID-19", "novel Coronavirus" and "Immune System". Based on the results of our searches conducted in databases, initially 1185 articles were selected. After screening the titles and abstracts of the retrieved articles and removal of the duplicate and irrelevant ones, 59 articles were included in the reveiew stage. Then, full text of eligible articles were put underclose scrutiny which led to the final selection of only 28 articles to be studied. Results According to our review, exercise can play a role in different ways against COVID-19 diseases and novel coronavirous, which is now recognized as a global problem. These roles include preventing some underlying diseases such as hypertension, coronary artery disease and diabetes and improving immunity. Exercise lowers cortisol levels in long term, which reduces the stress induced by COVID-19, which in turn strengthens the immune system. On the other hand, doing moderate- intensity exercise can strengthen the immune system in the long run, while low-intensity or high-intensity exercise types do not bring about similar degree of adaption. Conclusion It is necessary to pay special attention to exercise training in Covid-19 pandemic period. However, it should be noted that due to the novelty of this phenomenon, limited research has been done in this area to date and more research studies are required to be done in this regard. Practical implications of research It is best for people to stay home during Covid-19 pandemic period and to have 150 minutes of moderate-intensity regular exercise during the week to boost their immune system. Ethical considerations In this review research, the ethical issues of research and fiduciary have been observed. Conflict of interest We have no conflicts of interest to disclose. Acknowledgment No sources of funding were used to assist in the preparation of this article.