High-level football (soccer) players face intense physical demands that result in acute and residual fatigue, impairing their physical performance in subsequent matches. Further, top-class players are frequently exposed to match-congested periods where sufficient recovery times are not achievable. To evaluate training and recovery strategies, the monitoring of players’ recovery profiles is crucial. Along with performance and neuro-mechanical impairments, match-induced fatigue causes metabolic disturbances denoted by changes in chemical analytes that can be quantified in different body fluids such as blood, saliva, and urine, thus acting as biomarkers. The monitoring of these molecules might supplement performance, neuromuscular and cognitive measurements to guide coaches and trainers during the recovery period. The present narrative review aims to comprehensively review the scientific literature on biomarkers of post-match recovery in semi-professional and professional football players as well as provide an outlook on the role that metabolomic studies might play in this field of research. Overall, no single gold-standard biomarker of match-induced fatigue exists, and a range of metabolites are available to assess different aspects of post-match recovery. The use of biomarker panels might be suitable to simultaneously monitoring these broad physiological processes, yet further research on fluctuations of different analytes throughout post-match recovery is warranted. Although important efforts have been made to address the high interindividual heterogeneity of available markers, limitations inherent to these markers might compromise the information they provide to guide recovery protocols. Further research on metabolomics might benefit from evaluating the long-term recovery period from a high-level football match to shed light upon new biomarkers of post-match recovery.

The incidence and risk factors for poor outcome in patients with COVID are well known, as are the protective measures in high-risk populations. In contrast, the epidemiological and clinical behavior of this disease in the population of elite athletes who are the paradigm of good health is poorly understood. Data on COVID in athletes are scarce and have focused preferentially on the consequences on sports performance of confinement measures and on the pathophysiological risks of infected athletes. Real Madrid is a large elite sports institution with facilities in the City of Madrid where 600 athletes train daily. The incidence of COVID during a study period of 671 days of observation in athletes, professional or amateur, working in the institution has been 0,74 per 1,000 days of exposure. The disease has been asymptomatic or oligosymptomatic in all athletes and did not require any hospital admissions. The different teams did not have to suspend any of its sportive commitments for COVID during the study period and there was no evidence of outbreaks of internal transmission between members of the different teams.