Inclusion criteria for study.
|Aged between 11 and 20.|
|Train and compete at the same club during the 2018-2019 and 2019-2020 season.|
|Not part of a high performance sports programme during the 2018-2019 season.|
|The club where the athlete’s activity is based has a first team that competes in the highest regional category or above, or the athletes compete with their team in the highest federal regional category of their age or above during the 2019-2020 season.|