Physical Education and Sport Science Academic Group, National Institute of Education, Nanyang Technological University, Singapore, Singapore.
Department of Sport Sciences, Polytechnic Institute of Bragança, Bragança, Portugal.
Sci Rep. 2020 May 21;10(1):8464. doi: 10.1038/s41598-020-65494-z.
The aim of this study was to analyse the front-crawl arm-pull kinetics and kinematics, comparing it before and after post-activation potentiation (PAP), and the associations between variables describing of the arm-pull kinetics. Twelve male competitive swimmers were randomly assigned to perform two different warm-ups in a crossover manner: (i) non-PAP (control condition); and (ii) PAP (experimental condition). PAP consisted of 2 × 5 arm-pulls with resistance bands by both upper-limbs. Eight minutes later, participants underwent a 25 m all-out trial in front-crawl arm-pull. Kinetics (i.e., peak thrust, mean thrust and thrust-time integral) and kinematics (i.e., speed and speed fluctuation) were collected by an in-house customised system composed of differential pressure sensors, speedo-meter and underwater camera. There was a significant and large improvement of the arm-pull kinetics after completing the warm-up with PAP sets (0.010 < P < 0.054, 0.50 < d < 0.74). There were non-significant and small effects of PAP on speed (P = 0.307, d = 0.18) and speed fluctuation (P = 0.498, d = 0.04). Correlation coefficients among kinetic variables were significant with large associations (0.51 < R < 0.90, 0.001 < P < 0.088). In conclusion, warm-ups including PAP conditioning sets elicit a large improvement in the thrust, but with small improvement in performance. Variables used to characterise thrust are strongly correlated and hence can be used interchangeably.
本研究旨在分析自由泳划臂的动力学和运动学，比较其在激活后增强（PAP）前后的差异，并分析描述划臂动力学的变量之间的相关性。12 名男性竞技游泳运动员以交叉方式随机分为两组进行两种不同的热身：（i）非 PAP（对照条件）；和（ii）PAP（实验条件）。PAP 由两组上肢的阻力带完成 2×5 次划臂组成。8 分钟后，参与者以自由泳进行 25 米全力冲刺。动力学（即峰值推力、平均推力和推力时间积分）和运动学（即速度和速度波动）由一个由差压传感器、速度计和水下相机组成的内部定制系统收集。在完成 PAP 热身组后，划臂动力学有显著和较大的改善（0.010<P<0.054，0.50<d<0.74）。PAP 对速度（P=0.307，d=0.18）和速度波动（P=0.498，d=0.04）的影响不显著且较小。动力学变量之间的相关系数具有显著的大相关性（0.51<R<0.90，0.001<P<0.088）。总之，包括 PAP 调节组的热身可以显著提高推力，但对表现的改善较小。用于描述推力的变量具有很强的相关性，因此可以互换使用。
