Study population and recruitment
Inclusion criteria for the randomised groups were teams (1) participating in the adolescent or adult 2020 series (male 5th–8th leagues (out of 8 leagues), female 3rd–5th leagues (out of 5 leagues), male and female 16–19 series) in one regional district (Östergötland, Sweden), (2) with at least two scheduled training sessions per week, (3) that had not used an IPEP regularly the previous year. Inclusion criteria 1 and 2 were identical for the comparison group, but these teams had used an IPEP regularly (at least once per week) the previous year and planned to continue in the 2020 season. All players 14 years and older were eligible.Coaches for eligible teams (n=251) were approached via e-mail and telephone (Flow diagram over the inclusion and exclusion of teams and players in the study. F, female; IPEP, injury prevention exercise programme; M, male.