Department of Sport Exercise and Rehabilitation, Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, United Kingdom.
English Institute of Sport, Manchester, United Kingdom.
J Strength Cond Res. 2018 Oct;32(10):2708-2714. doi: 10.1519/JSC.0000000000002497.
Harden, M, Wolf, A, Russell, M, Hicks, KM, French, D, and Howatson, G. An evaluation of supramaximally loaded eccentric leg press exercise. J Strength Cond Res 32(10): 2708-2714, 2018-High-intensity eccentric exercise is a potent stimulus for neuromuscular adaptation. A greater understanding of the mechanical stimuli afforded by this exercise will aid the prescription of future eccentric training regimens. This study sought to investigate the mechanical characteristics of supramaximally loaded eccentric exercise when using a custom-built leg press machine. Using a within-subject, repeated-measures design, 15 strength trained subjects (age, 31 ± 7 years; height, 180.0 ± 6.8 cm; body mass, 81.5 ± 13.9 kg) were assessed under 3 different conditions: low (LO), moderate (MOD), and high (HI) intensity, which were equivalent in intensity to 110, 130, and 150%, respectively, of peak force during an isometric maximal voluntary contraction (IMVC) performed on leg press at 90° knee flexion. All loading conditions demonstrated a similar pattern of mechanical profile; however, the variables underpinning each profile showed significant (p < 0.01) load-dependent response (LO vs. MOD, MOD vs. HI, LO vs. HI) for all variables, except for average acceleration. Average force associated with each loading conditions exceeded IMVC but equated to a lower intensity than what was prescribed. Repetitions under higher relative load intensity stimulated greater average force output, faster descent velocity, greater magnitude of acceleration, shorter time under tension, and a decline in force output at the end range of motion. This research provides new data regarding the fundamental mechanical characteristics underpinning supramaximally loaded eccentric leg press exercise. The information gathered in the study provides a foundation for practitioners to consider when devising loading strategies and implementing or evaluating supramaximally loaded eccentric exercise when using a similar exercise and device.
哈登、沃尔夫、拉塞尔、希克斯、弗伦奇和豪特森。最大负荷离心腿推练习的评估。J 力量与调节研究 32（10）：2708-2714，2018-高强度离心运动是神经肌肉适应的有力刺激。对这种运动所提供的机械刺激有更深入的了解将有助于制定未来的离心训练方案。本研究旨在探讨使用定制的腿推机进行最大负荷离心运动的机械特性。采用单因素重复测量设计，对 15 名力量训练有素的受试者（年龄 31±7 岁；身高 180.0±6.8cm；体重 81.5±13.9kg）进行评估，共 3 种不同的条件：低（LO）、中（MOD）和高（HI）强度，分别相当于腿推 90°膝关节屈曲等长最大自愿收缩（IMVC）中 110%、130%和 150%的峰值力。所有加载条件均表现出相似的机械特性；然而，支撑每个特性的变量表现出显著的（p<0.01）负载依赖性反应（LO 与 MOD、MOD 与 HI、LO 与 HI），除平均加速度外。与每个加载条件相关的平均力均超过 IMVC，但强度低于规定的强度。在较高的相对负荷强度下进行重复运动刺激了更大的平均力输出、更快的下降速度、更大的加速度幅度、更短的张力时间和运动末端力输出的下降。这项研究提供了关于最大负荷离心腿推练习的基本机械特性的新数据。该研究收集的信息为从业人员提供了一个基础，以便在使用类似的设备和练习制定加载策略并实施或评估最大负荷离心运动时，考虑到这一点。
