Table 2 Operational definitions
Training sessionTeam training under the supervision of the coaching staff that involved physical activity.
    Football trainingFootball-specific training using a ball.
    Strength trainingTraining with main focus on increasing player strength.
    Endurance trainingTraining with main focus on increasing player aerobic or anaerobic capacity.
    Recovery trainingTraining with low intensity and focus on recovery.
MatchCompetitive match against another team.
InjuryInjury resulting from playing football and leading to a player being unable to fully participate in future training or match play (ie, time loss injury).
    RehabilitationA player was considered injured until team medical staff allowed full participation in training and availability for match selection.
    Re-injuryInjury of the same type and at the same site as a previous injury that the player had suffered from previously prior to or during the tournament.
    Early recurrent injuryRe-injury within two months of return to full participation after the index injury.
    Late recurrent injuryRe-injury more than two months after return to full participation from the index injury.
    Slight injuryInjury causing the player to interrupt a training session or match but was able to fully participate the day after injury (0 days absence).
    Minimal injuryInjury causing 1–3 days absence from training and match play.
    Mild injuryInjury causing 4–7 days absence from training and match play.
    Moderate injuryInjury causing 8–28 days absence from training and match play.
    Severe injuryInjury causing >28 days absence from training and match play.
    Traumatic injuryInjury with sudden onset and known cause.
    Overuse injuryInjury with insidious onset and without any known trauma.
    Contact injuryTraumatic injury resulting from contact with another player or object.
    Non-contact injuryTraumatic injury not resulting from contact with another player or object.
    Foul play injuryMatch injury resulting from foul play according to the decision of the referee.
Injury incidenceNumber of injuries per 1000 player hours [(Σ injuries/Σ exposure hours) ×1000].