Effect of Increasing the Number of Substitutions on Physical Performance during Periods of Congested Fixtures in Football.

(I) This study aimed to evaluate the impact on physical demands induced by FIFA's new rule implemented based on the number of substitutions caused by COVID-19. (II) Sixty-six matches were analysed in peak periods (microcycles of three matches in a week) in the competition period before and after the pandemic. The variables collected were organised by team (22 from LaLigaTM SmartBank 2019-2020) for a total of 132 team records and 1077 player performance reports using a multi-camera tracking system and Mediacoach® software. Physical performance variables were analysed in the first half, second half and whole match, thus determining the individual and collective performances of the team. (III) This study shows how, despite the increase in substitutions allowed with the new rule, physical performance increased in some variables in the congested periods (e.g., total distance run and distance run in the first and second halves). Additionally, the players' physical performance involved in a substitution was greater than it was for players who completed the game. (IV) The new substitution rule helps to maintain and even improve physical performance. This measure could improve intensity levels in both individual and team performance. It could even safeguard the physical integrity of the players by reducing the risk of injury, as fewer players have to play the full match.

How has COVID-19 modified training and mood in professional and non-professional football players?

BACKGROUND: Coronavirus disease 2019 (COVID-19) has restricted freedom of movement with several countries 'locked down' worldwide. During this isolation period or quarantine, habits have been modified. This might have had negative effects on physiological variables but also influenced numerous emotional aspects, especially in elite athletes, which can have a negative impact on training and sleep quality, affecting their performance. METHODS: 175 Spanish professional and non-professional association football players answered an online survey about demographic and training habits, as well as two validated questionnaires to assess psychological variables (POMS and WLEIS-S). RESULTS: The results showed that the confinement period reduced the load of training (p < 0.01), and modified the sleeping behaviour (both, sleep time (p < 0.05) and quality (p < 0.001)) across soccer players. Higher emotional intelligence (EI) values were positively related to training variables and strongly correlated with the mood. Interestingly, athletes' mood was affected differently depending on gender. CONCLUSION: We found that confinement period affects both, training load and recovery process and that mood states and EI could predict the training variables and performance of top-level football players.