Department of Physical Activity Sciences, Research Nucleus in Health, Physical Activity and Sport, Universidad de Los Lagos (University of Los Lagos), Osorno, Chile.
Research Group Planning and Assessment of Training and Athletic Performance, Pontifical University of Salamanca, Salamanca, Spain.
J Strength Cond Res. 2018 Apr;32(4):885-893. doi: 10.1519/JSC.0000000000002467.
Ramirez-Campillo, R, Alvarez, C, García-Pinillos, F, Sanchez-Sanchez, J, Yanci, J, Castillo, D, Loturco, I, Chaabene, H, Moran, J, and Izquierdo, M. Optimal reactive strength index: is it an accurate variable to optimize plyometric training effects on measures of physical fitness in young soccer players? J Strength Cond Res 32(4): 885-893, 2018-This study aimed to compare the effects of drop-jump training using a fixed drop-box height (i.e., 30-cm [FIXED]) vs. an optimal (OPT) drop-box height (i.e., 10-cm to 40-cm: generating an OPT reactive strength index [RSI]) in youth soccer players' physical fitness. Athletes were randomly allocated to a control group (n = 24; age = 13.7 years), a fixed drop-box height group (FIXED, n = 25; age = 13.9 years), or an OPT drop-box height group (OPT, n = 24; age = 13.1 years). Before and after 7 weeks of training, tests for the assessment of jumping (countermovement jump [CMJ], 5 multiple bounds), speed (20-m sprint time), change of direction ability (CODA [Illinois test]), strength {RSI and 5 maximal squat repetition test (5 repetition maximum [RM])}, endurance (2.4-km time trial), and kicking ability (maximal kicking distance) were undertaken. Analyses revealed main effects of time for all dependent variables (p < 0.001, d = 0.24-0.72), except for 20-m sprint time. Analyses also revealed group × time interactions for CMJ (p < 0.001, d = 0.51), depth jump (DJ) (p < 0.001, d = 0.30), 20-m sprint time (p < 0.001, d = 0.25), CODA (p < 0.001, d = 0.22), and 5RM (p < 0.01, d = 0.16). Post hoc analyses revealed increases for the FIXED group (CMJ: 7.4%, d = 0.36; DJ: 19.2%, d = 0.49; CODA: -3.1%, d = -0.21; 5RM: 10.5%, d = 0.32) and the OPT group (CMJ: 16.7%, d = 0.76; DJ: 36.1%, d = 0.79; CODA: -4.4%, d = -0.34; 5RM: 18.1%, d = 0.47). Post hoc analyses also revealed increases for the OPT group in 20-m sprint time (-3.7%, d = 0.27). Therefore, to maximize the effects of plyometric training, an OPT approach is recommended. However, using adequate fixed drop-box heights may provide a rational and practical alternative.
拉米雷斯 - 坎皮洛、阿尔瓦雷斯、加西亚 - 皮尼洛斯、F、桑切斯 - 桑切斯、J、扬西、J、卡斯蒂略、D、洛图尔科、I、沙班内、H、莫兰、J 和伊齐亚尔多、M. 最佳反应强度指数：它是优化增强式训练对年轻足球运动员身体素质影响的准确变量吗？J 力量与调节研究 32(4):885-893,2018-本研究旨在比较使用固定跳箱高度（即 30 厘米[固定]）与最佳（OPT）跳箱高度（即 10 厘米至 40 厘米：生成最佳反应强度指数[RSI]）的跳下训练对青年足球运动员身体素质的影响。运动员被随机分配到对照组（n = 24；年龄 = 13.7 岁）、固定跳箱高度组（FIXED，n = 25；年龄 = 13.9 岁）或最佳跳箱高度组（OPT，n = 24；年龄 = 13.1 岁）。在 7 周的训练前后，进行了跳跃（深蹲跳[CMJ]、5 次多跳）、速度（20 米冲刺时间）、变向能力（伊利诺伊测试[CODA]）、力量[RSI 和 5 次最大深蹲重复测试（5 次重复最大[RM]）]、耐力（2.4 公里计时赛）和踢球能力（最大踢球距离）的测试。分析显示，所有因变量均存在时间的主要影响（p < 0.001，d = 0.24-0.72），除了 20 米冲刺时间。分析还显示了 CMJ（p < 0.001，d = 0.51）、深度跳（DJ）（p < 0.001，d = 0.30）、20 米冲刺时间（p < 0.001，d = 0.25）、CODA（p < 0.001，d = 0.22）和 5RM（p < 0.01，d = 0.16）的组间时间交互作用。事后分析显示，固定组（CMJ：7.4%，d = 0.36；DJ：19.2%，d = 0.49；CODA：-3.1%，d = -0.21；5RM：10.5%，d = 0.32）和 OPT 组（CMJ：16.7%，d = 0.76；DJ：36.1%，d = 0.79；CODA：-4.4%，d = -0.34；5RM：18.1%，d = 0.47）均有增加。事后分析还显示，OPT 组 20 米冲刺时间也有所增加（-3.7%，d = 0.27）。因此，为了最大限度地发挥增强式训练的效果，建议采用最佳方法。然而，使用适当的固定跳箱高度可能是一种合理且实用的替代方法。
