Determinants of cardiorespiratory fitness measured by cardiopulmonary exercise testing in COVID-19 survivors: A systematic review with meta-analysis and meta‑regression.

•Cardiorespiratory fitness measured by cardiopulmonary exercise testing is consistently impaired in COVID-19 survivors.•The degree of reduction of cardiorespiratory fitness is inversely associated with age, time post-COVID-19, disease severity, presence of dyspnea, and reduced exercise capacity.•Future research should investigate the mechanisms of cardiorespiratory fitness reduction in addition to investigating possible therapeutic strategies to maximize fitness post COVID-19.