Impact of (long) COVID on athletes' performance: a prospective study in elite football players.

Objectives: To investigate possible persistent performance deficits after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in elite athletes.

Methods: A prospective cohort study in three Belgian professional male football teams was performed during the 2020 - 2021 season. Participants were submitted to and sprint tests and an aerobic performance test (the Yo-Yo Intermittent Recovery test (YYIR)).

Association between SARS-COV-2 infection and muscle strain injury occurrence in elite male football players: a prospective study of 29 weeks including three teams from the Belgian professional football league.

Objectives: The aim of this study was to investigate the association between SARS-CoV-2 infection and muscle strain injury in elite athletes.

Methods: A prospective cohort study in three Belgian professional male football teams was performed during the first half of the 2020-2021 season (June 2020-January 2021). Injury data were collected using established surveillance methods.

Multilevel modelling of longitudinal changes in isokinetic knee extensor and flexor strength in adolescent soccer players.

The purpose of the study was to model the longitudinal development of knee extension (KE) and flexion (KF) strength in adolescent soccer players. A mixed-longitudinal sample composed of 67 soccer players aged 11.0-13.

Developmental Changes in Isometric Strength: Longitudinal Study in Adolescent Soccer Players.

This study aimed to examine longitudinal changes in isometric strength of the knee extensors (ImKE) and knee flexors (ImKF) at 30° and 60°. The sample was composed of 67 players aged 11.0-13.

Multivariate Relationships among Morphology, Fitness and Motor Coordination in Prepubertal Girls.

Motor coordination and physical fitness are multidimensional concepts which cannot be reduced to a single variable. This study evaluated multivariate relationships among morphology, physical fitness and motor coordination in 74 pre-pubertal girls 8.0-8.