Int J Sports Physiol Perform. 2018 Jul 1;13(6):763-769. doi: 10.1123/ijspp.2017-0610. Epub 2018 Jul 10.
To examine the reliability of peak velocity (PV), mean propulsive velocity (MPV), and mean velocity (MV) in the development of load-velocity profiles (LVP) in the full-depth free-weight back squat performed with maximal concentric effort.
Eighteen resistance-trained men performed a baseline 1-repetition maximum (1-RM) back-squat trial and 3 subsequent 1-RM trials used for reliability analyses, with 48-h intervals between trials. 1-RM trials comprised lifts from 6 relative loads including 20%, 40%, 60%, 80%, 90%, and 100% 1-RM. Individualized LVPs for PV, MPV, or MV were derived from loads that were highly reliable based on the following criteria: intraclass correlation coefficient (ICC) >.70, coefficient of variation (CV) ≤10%, and Cohen d effect size (ES) <0.60.
PV was highly reliable at all 6 loads. MPV and MV were highly reliable at 20%, 40%, 60%, 80%, and 90% but not 100% 1-RM (MPV: ICC = .66, CV = 18.0%, ES = 0.10, SEM = 0.04 m·s; MV: ICC = .55, CV = 19.4%, ES = 0.08, SEM = 0.04 m·s). When considering the reliable ranges, almost perfect correlations were observed for LVPs derived from PV (r = .91-.93), MPV (r = .92-.94), and MV (r = .94-.95). Furthermore, the LVPs were not significantly different (P > .05) between trials or movement velocities or between linear regression versus 2nd-order polynomial fits.
PV, MPV, and MV are reliable and can be utilized to develop LVPs using linear regression. Conceptually, LVPs can be used to monitor changes in movement velocity and employed as a method for adjusting sessional training loads according to daily readiness.
研究在使用最大向心力量进行全深度自由重量深蹲时，峰值速度（PV）、平均推进速度（MPV）和平均速度（MV）在负荷-速度曲线（LVP）发展中的可靠性。
18 名受过抗阻训练的男性进行了基线 1 次重复最大（1-RM）深蹲试验和随后的 3 次 1-RM 试验，用于可靠性分析，试验之间间隔 48 小时。1-RM 试验包括从 6 个相对负荷中进行举重，包括 20%、40%、60%、80%、90%和 100%的 1-RM。根据以下标准，从高度可靠的负荷中得出个体 LVP 用于 PV、MPV 或 MV：组内相关系数（ICC）>.70、变异系数（CV）≤10%，和 Cohen d 效应量（ES）<.60。
在所有 6 个负荷中，PV 具有高度可靠性。在 20%、40%、60%、80%和 90%时，MPV 和 MV 具有高度可靠性，但在 100% 1-RM 时不具有高度可靠性（MPV：ICC=.66、CV=18.0%、ES=0.10、SEM=0.04 m·s；MV：ICC=.55、CV=19.4%、ES=0.08、SEM=0.04 m·s）。当考虑可靠范围时，PV（r=.91-.93）、MPV（r=.92-.94）和 MV（r=.94-.95）得出的 LVP 几乎呈现出完美的相关性。此外，试验之间、运动速度之间或线性回归与二阶多项式拟合之间的 LVP 没有显著差异（P>.05）。
PV、MPV 和 MV 是可靠的，可以用于使用线性回归来开发 LVP。从概念上讲，LVP 可用于监测运动速度的变化，并作为根据日常准备情况调整会议训练负荷的方法。
