Reliability of Maximal Back Squat and Power Clean Performances in Inexperienced Athletes

Abstract Comfort, P and McMahon, JJ. Reliability of maximal back squat and power clean performances in inexperienced athletes. J Strength Cond Res 29(11): 3089–3096, 2015—The aim of the study was to determine between-session reliability of maximal weight lifted during the back squat and power clean, in inexperienced athletes, and to identify the smallest detectable difference between sessions. Forty-four collegiate athletes (men: n = 32; age: 21.5 ± 2.0 years; height: 180.0 ± 6.1 cm; body mass: 81.01 ± 7.42 kg; women: n = 12; age: 21.0 ± 1.9 years; height: 169.0 ± 5.2 cm; body mass: 62.90 ± 7.46 kg) participated in this study. One repetition maximum (1RM) back squat and power cleans were each performed twice on separate days, 3–5 days apart. Paired samples' t tests revealed no significant differences between trial 1 and trial 2 of the power clean (70.55 ± 24.24 kg, 71.22 ± 23.87 kg, p > 0.05, power = 0.99) and the back squat (130.32 ± 34.05 kg, 129.82 ± 34.07 kg, p > 0.05, power = 1.0). No differences in reliability or measurement error were observed between men and women. Intraclass correlation coefficients (ICCs) demonstrated a high reliability (ICC = 0.997, p < 0.001) for between-session 1RM power clean with an R 2 of 0.987; similarly, high reliability was observed for between-session back squat performances (ICC = 0.994, p < 0.001), with an R 2 of 0.978. The smallest detectable difference between sessions for both measures were ∼5%, highlighting that coaches and researchers should look for a change of >5% to identify a meaningful change in both maximal back squat and power clean performance.