School of Behavioural and Health Sciences, Australian Catholic University, Brisbane 4014, Queensland, Australia.
Department of Sports Sciences and Physical Conditioning, Faculty of Education, Universidad Católica de la Santísima Concepción, Concepción 2850, Chile.
Int J Environ Res Public Health. 2020 Sep 7;17(18):6509. doi: 10.3390/ijerph17186509.
Exercise velocity and relative velocity loss thresholds (VLTs) are commonly used in velocity-based resistance training. This study aims to quantify the between-day reliability of 10%, 20%, and 30% VLTs on kinetic and kinematic outputs, changes in external load, and repetition characteristics in well-trained athletes. Using a repeated, counter-balanced crossover design, twelve semi-professional athletes completed five sets of the back squat with an external load corresponding to a mean concentric velocity of ~0.70 m·s and a VLT applied. The testing sessions were repeated after four weeks of unstructured training to assess the long-term reliability of each VLT. A coefficient of variation (CV) <10% was used to classify outputs as reliable. Kinetic and kinematic outputs and external load were largely reliable, with only peak power during sets 2-5 within the 10% VLT condition demonstrating a CV >10% (CV: 11.14-14.92%). Alternatively, the repetitions completed within each set showed large variation (CV: 18.92-67.49%). These findings demonstrate that by utilizing VLTs, kinetic and kinematic outputs can be prescribed and replicated across training mesocycles. Thus, for practitioners wishing to reliably control the kinetic and kinematic stimulus that is being applied to their athletes, it is advised that a velocity-based approach is used.
运动速度和相对速度损失阈值（VLTs）常用于基于速度的阻力训练。本研究旨在量化 10%、20%和 30%VLT 在动力学和运动学输出、外部负荷变化以及训练有素的运动员重复特征方面的日间可靠性。使用重复、平衡交叉设计，十二名半职业运动员完成了五组后深蹲，外部负荷对应于约 0.70m·s 的平均向心速度和应用 VLT。四周无结构训练后重复测试，以评估每个 VLT 的长期可靠性。变异系数（CV）<10%被用于将输出分类为可靠。动力学和运动学输出以及外部负荷在很大程度上是可靠的，只有在 10%VLT 条件下的第 2-5 组中的峰值功率显示 CV>10%（CV：11.14-14.92%）。相反，每组内完成的重复次数显示出很大的变化（CV：18.92-67.49%）。这些发现表明，通过利用 VLT，可以在训练中周期内规定和复制动力学和运动学输出。因此，对于希望可靠地控制向运动员施加的动力学和运动学刺激的从业者，建议使用基于速度的方法。
