Clark Kenneth, Cahill Micheál, Korfist Christian, Whitacre Tyler
Department of Kinesiology, West Chester University, West Chester, Pennsylvania.
Department of Athletics, Jesuit College Preparatory School, Dallas, Texas; and.
J Strength Cond Res. 2021 Jul 1;35(7):1856-1864. doi: 10.1519/JSC.0000000000003051.
Clark, K, Cahill, M, Korfist, C, and Whitacre, T. Acute kinematic effects of sprinting with motorized assistance. J Strength Cond Res 35(7): 1856-1864, 2021-Although assisted sprinting has become popular for training maximum velocity, the acute effects are not fully understood. To examine this modality, 14 developmental male sprinters (age: 18.0 ± 2.5 years, 100-m personal best: 10.80 ± 0.31 seconds) performed maximal trials, both unassisted and assisted with a motorized towing device using a load of 7 kg (9.9 ± 0.9% body mass). Significant increases in maximum velocity (+9.4%, p ≤ 0.001, d = 3.28) occurred due to very large increases in stride length (+8.7%, p ≤ 0.001, d = 2.04) but not stride rate (+0.7%, p = 0.36, d = 0.11). Stride length increased due to small changes in distance traveled by the center of mass during ground contact (+3.7%, p ≤ 0.001, d = 0.40) combined with very large changes in distance traveled by the center of mass during flight (+13.1%, p ≤ 0.001, d = 2.62). Although stride rate did not demonstrate significant between-condition differences, the combination of contact and flight time was different. Compared to unassisted sprinting, assisted sprinting caused small but significant decreases in contact time (-5.2%, p ≤ 0.001, d = 0.49) and small but significant increases in flight time (+3.4%, p < 0.05, d = 0.58). Sprinting with motorized assistance elicited supramaximal velocities with decreased contact times, which may represent a neuromuscular stimulus for athletes attempting to enhance sprinting performance. Future research is needed to investigate the effects of this modality across various assistive loads and athletic populations, and to determine the longitudinal efficacy as a training method for improving maximum-velocity sprinting performance.
克拉克、K、卡希尔、M、科尔菲斯特、C和惠塔克、T。电动助力短跑的急性运动学效应。《力量与体能研究杂志》35(7): 1856 - 1864，2021年——尽管助力短跑已成为训练最大速度的流行方式，但其急性效应尚未完全了解。为了研究这种方式，14名发育阶段的男性短跑运动员（年龄：18.0 ± 2.5岁，100米个人最好成绩：10.80 ± 0.31秒）进行了最大强度测试，包括无助力和使用7千克（9.9 ± 0.9%体重）的电动牵引装置助力的情况。由于步幅大幅增加（+8.7%，p ≤ 0.001，d = 2.04），最大速度显著提高（+9.4%，p ≤ 0.001，d = 3.28），但步频未显著提高（+0.7%，p = 0.36，d = 0.11）。步幅增加是由于着地时质心移动距离的微小变化（+3.7%，p ≤ 0.001，d = 0.40）以及腾空时质心移动距离的大幅变化（+13.1%，p ≤ 0.001，d = 2.62）共同作用的结果。尽管步频在不同条件下未显示出显著差异，但着地时间和腾空时间的组合有所不同。与无助力短跑相比，助力短跑导致着地时间小幅但显著减少（-5.2%，p ≤ 0.001，d = 0.49），腾空时间小幅但显著增加（+3.4%，p < 0.05，d = 0.58）。电动助力短跑能产生超最大速度且着地时间减少，这可能对试图提高短跑成绩的运动员构成神经肌肉刺激。未来需要开展研究，以调查这种方式在不同助力负荷和运动员群体中的效果，并确定其作为提高最大速度短跑成绩的训练方法的长期有效性。
