The purpose of this study was to evaluate intrasession reliability of countermovement jump (CMJ) and isometric mid-thigh pull (IMTP) force–time characteristics, as well as relationships between CMJ and IMTP metrics. Division I sport and club athletes (n = 112) completed two maximal effort CMJ and IMTP trials, in that order, on force plates. Relative and absolute reliability were assessed using intraclass correlation coefficients (ICCs) > 0.80 and coefficients of variation (CVs) < 10%. Intrasession reliability was acceptable for the majority of the CMJ force–time metrics except for concentric rate of force development (RFD), eccentric impulse and RFD, and lower limb stiffness. The IMTP’s time to peak force, instantaneous force at 150 ms, instantaneous net force, and RFD measures were not reliable. Statistically significant weak to moderate relationships (r = 0.20–0.46) existed between allometrically scaled CMJ and IMTP metrics, with the exception of CMJ eccentric mean power not being related with IMTP performances. A majority of CMJ and IMTP metrics met acceptable reliability standards, except RFD measures which should be used with caution. Provided CMJs and IMTPs are indicative of distinct physical fitness capabilities, it is suggested to monitor athlete performance in both tests via changes in those variables that demonstrate the greatest degree of reliability.

中文翻译：

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识别运动员的可靠和相关的力量时间度量标准-对大腿中部等距拉力和反向运动跳跃的考虑

这项研究的目的是评估反向运动跳跃（CMJ）和大腿中部等距（IMTP）力时特性的会话间可靠性，以及CMJ和IMTP指标之间的关系。第一分部体育和俱乐部运动员（n= 112）在测力板上按此顺序完成了两个最大的CMJ和IMTP试验。使用组内相关系数（ICC）> 0.80和变异系数（CV）<10％评估相对和绝对可靠性。对于大多数CMJ力-时间指标，术中可靠性是可以接受的，但同心力发展（RFD），偏心冲动和RFD以及下肢僵硬除外。IMTP达到峰值力的时间，150 ms的瞬时力，瞬时净力和RFD措施都不可靠。具有统计意义的弱到中度关系（r异度缩放比例的CMJ和IMTP度量之间存在= 0.20–0.46），但CMJ偏心平均功率与IMTP性能无关。CMJ和IMTP的大多数指标符合可接受的可靠性标准，但RFD措施除外，应谨慎使用。如果CMJ和IMTP表示出独特的身体适应能力，则建议通过证明最大程度可靠性的那些变量的变化来监视两项测试中的运动员表现。