Neuromuscular Research Lab, Faculty of Human Kinetics, University of Lisbon, Dafundo, Portugal; and.
CIPER, Faculty of Human Kinetics, University of Lisbon, Dafundo, Portugal.
J Strength Cond Res. 2023 Aug 1;37(8):1559-1565. doi: 10.1519/JSC.0000000000004437. Epub 2023 Feb 1.
Mendonca, GV, Fitas, A, Santos, P, Gomes, M, and Pezarat-Correia, P. Predictive equations to estimate relative load based on movement velocity in males and females: accuracy of estimation for the Smith machine concentric back squat. J Strength Cond Res 37(8): 1559-1565, 2023-We sought to determine the validity of using the Smith machine bar velocity to estimate relative load during the concentric back squat performed by adult male and female subjects. Thirty-two subjects (16 men: 23.3 ± 3.8 and 16 women: 26.1 ± 2.7 years) were included. The load-velocity relationship was extracted for all subjects individually. Mean concentric velocity (MCV), combined with sex, was used to develop equations predictive of relative load (% one repetition maximum [1RM]). Prediction accuracy was determined with the mean absolute percent error and Bland-Altman plots. Relative strength was similar between the sexes. However, male subjects exhibited faster concentric MCV at 1RM ( p < 0.05). Mean concentric velocity and the sex-by-MCV interaction were both significant predictors of %1RM ( p < 0.0001), explaining 89% of its variance. The absolute error was similar between the sexes (men: 9.4 ± 10.0; women: 8.4 ± 10.5, p > 0.05). The mean difference between actual and predicted %1RM in Bland-Altman analysis was nearly zero in both sexes and showed no heteroscedasticity. The limits of agreement in both men and women were of approximately ±15%. Taken together, it can be concluded that sex should be taken into consideration when aiming at accurate prescription of relative load based on movement velocity. Moreover, predicting relative load from MCV and sex provides an error of approximately 10% in assessments of relative load in groups of persons. Finally, when used for individual estimations, these equations may implicate a considerable deviation from the actual relative load, and this may limit their applicability to training conditions in which extreme accuracy is required (i.e., more advanced lifters and athletes).
门东卡、GV、菲塔斯、A、桑托斯、P、戈麦斯、M 和佩扎拉-科雷亚、P. 基于运动速度预测男性和女性相对负荷的方程：史密斯机同心深蹲中估计的准确性。J 力量与体能研究 37(8):1559-1565, 2023-我们旨在确定在成年男性和女性受试者进行史密斯机同心深蹲时，使用史密斯机杆速度来估计相对负荷的有效性。共纳入 32 名受试者（16 名男性：23.3 ± 3.8 岁和 16 名女性：26.1 ± 2.7 岁）。单独为所有受试者提取了负荷-速度关系。平均向心速度（MCV）与性别相结合，用于开发预测相对负荷（%1RM）的方程。通过平均绝对百分比误差和 Bland-Altman 图确定预测准确性。男女之间的相对力量相似。然而，男性受试者在 1RM 时表现出更快的向心 MCV（p<0.05）。平均向心速度和 MCV 的性别交互作用都是%1RM 的显著预测因子（p<0.0001），解释了其 89%的方差。男女之间的绝对误差相似（男性：9.4 ± 10.0；女性：8.4 ± 10.5，p>0.05）。在 Bland-Altman 分析中，实际和预测的%1RM 之间的平均差异在两性中几乎为零，且没有异方差性。两性的一致性界限约为±15%。综上所述，在基于运动速度准确规定相对负荷时，应考虑性别因素。此外，从 MCV 和性别预测相对负荷可以在人员组中提供大约 10%的相对负荷评估误差。最后，当用于个体估计时，这些方程可能会导致与实际相对负荷的相当大偏差，这可能会限制它们在需要极高准确性的训练条件下的适用性（即，更高级别的举重运动员和运动员）。
