Reliability And Usefulness Of Half-Squat 1rm Estimation Through Movement Velocity In U18 Soccer Players

Introduction: Assessment of strength in youth athletes using a safety, time-efficient and reliable test is crucial for strength and conditioning professionals. The purpose of this study was to examine the reliability of the one-repetition maximum (1RM) estimation through movement velocity in youth soccer players. In addition, the relationships between 1RM estimation with peak power (PP), jumping and sprinting performance were checked. Material and methods: Twenty-two youth soccer players (16.8 +/- 0.6 years) took part in the study. Participants completed a 1RM estimation in the half-squat, squat jump (SJ), countermovement jump (CMJ) and 30m sprint in three different occasions. Results: The 1RM estimation showed good absolute (SEM<10%) and relative (ICC>0.7) reliability scores. The estimated 1RM value was significantly lower in the trial 1 compared to the trials 2 and 3. The estimated 1RM and the PP output showed significant correlations (r=0.538-0.560) with jumping and sprinting performance. Discussion: These data suggest the necessity to perform at least one familiarization session to obtain a reliable 1RM estimation through movement velocity in youth soccer players. Once youth soccer players are familiarized with the 1RM estimation protocol, coaches could use this evaluation to obtain a reliable measure of players' maximal strength in a time-efficient way.