COVID-19(25) SARS-CoV-2(13) Infection(13) Symptom(11) prevention(10) public health(9) patients(9) illness(9) Result(9) physical activity(9) Football(8) protocol(8) develop(7) diagnosed(7) soccer(7) SARS-COV-2 infection(7) sports and exercise medicine(6) exercise(6) evaluated(6) moderate(6) elite performance(6) respiratory(6) COVID-19 pandemic(6) Transmission(6) Frequency(6) healthy(6) Athletes(5) no difference(5) PCR(5) male(5)