Sport, exercise and COVID-19, the disease caused by the SARS-CoV-2 coronavirus

No health emergency in living memory has ever had greater repercussions for our health, economy and the way we live than the COVID-19 pandemic caused by SARS-CoV-2, commonly re¬ferred to as the “coronavirus”. › COVID-19 has many links to sport and exercise: sports events such as the champions league quarter final between Atalanta Bergamo and FC Valencia on the 19.02.2020 have contributed to the virus spread; control measures such as lockdowns and clo¬sures of gyms and other sport facilities have altered our exercise behaviours; major sporting events including the Tokio Olympics have been cancelled or postponed; sports and fitness providers such as sports clubs, gyms and swimming pools have been hard hit. › In this review, we will answer from the perspective of sport and exercise five questions in relation to COVID-19. The ques¬tions deal with 1) how SARS-CoV-2 targets via its spike protein ACE2-expressing human cells, 2) the COVID-19 disease caused by it, 3) the COVID-19 pandemic and attempts to control it, 4) how the immune system responds to SARS-CoV-2 and how we can boost the immune system through moderate exercise training, 5) advice for exercise during the pandemic for healthy adults, athletes and elderly, and possible control measures to help to return to normal sport and exercise at the end of the pandemic before herd immunity or mass vaccination have been achieved.