Exercise Training, Immune System, and Coronavirus

The novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) which caused COVID-19, is a pandemic that threatens human societies in many ways. It seems that the main strategy of managing coronavirus at present is to prevent infection. In addition to improving physical fitness, moderate-intensity exercise boosts the cell-mediated and humoral immune system responses, especially in people with weakened immune systems who are at risk of coronavirus implications such as the elderly, obese people and those with chronic diseases. Therefore, performing regular exercise during life span can be considered as an effective strategy to prevent viral diseases such as COVID-19. On the other hand, home quarantine and non-use of public sports setting reduce physical fitness, circadian rhythm disturbances, sleep disturbances, depression, increased sedentary behaviors and impair the balance of energy received and consumed, which leads to a weakened immune system and a more severe risk of complications from COVID-19 disease. Performing moderate-intensity exercise at home during an outbreak can be an effective strategy in counteracting these complications. In addition, moderate-intensity exercise is effective in improving the immune system and counteracting the effects of coronavirus directly by enhancing the immune system, antioxidant defenses and anti-inflammatory responses, and as well as indirectly by reducing anxiety, improving mood and modulating fat profile and insulin sensitivity.