Athletes with mild post-COVID-19 symptoms experience increased respiratory and metabolic demands: Α cross-sectional study oleh Vasileios T. Stavrou, Astara Kyriaki, George D. Vavougios, Ioannis G. Fatouros, George S. Metsios, Konstantinos Kalabakas, Dimitrios Karagiannis, Zoe Daniil, Konstantinos I. Gourgoulianis, George Βasdekis