Impaired Cardiorespiratory Fitness of Elite Athletes after Asymptomatic or Mild SARS-CoV-2 Infection

Background and Objectives: The aim of the study was to evaluate the health status of professional athletes after recovering from COVID-19 and the impact that SARS-CoV-2 had on their overall cardiorespiratory fitness, which was done by conducting cardiopulmonary exercise testing (CPET). Materials and Methods: A total of twenty-seven professional basketball players (Euroleague Basketball and the ABA League) participated in the study. CPET was performed before (as part of their regular preparticipation exam, during the pre-season period), as well as after SARS-CoV-2 infection (after two weeks of home isolation, during the competitive part of the season). CPET was performed on a treadmill, while cardiovascular, respiratory, and metabolic functions were evaluated by using a breath-by-breath analysis technique (Quark CPET system manufactured by Cosmed, Rome, Italy). Results: Maximal oxygen consumption and aerobic efficiency were significantly reduced after SARS-CoV-2 infection (p = 0.000). An obvious decrease in oxygen pulse was observed during CPET after recovering from COVID-19 (p = 0.001), as was deterioration of ventilatory efficiency. Internal respiration was the most negatively affected. An early transition from aerobic to anaerobic mechanisms of creating energy for work and intensive metabolic fatigue were obvious after SARS-CoV-2 infection. Conclusions: Although it was believed that SARS-CoV-2 only affects the cardiopulmonary status of the elderly population and people with associated comorbidities, it is clear from this research that professional athletes can also be at certain risk. Even though no pathological cardiovascular and respiratory changes were found in athletes after COVID-19, results showed significantly decreased cardiorespiratory fitness, with an emphasis on internal respiration.