研究目的：探究基于跳深练习的激活后增强效应（PAP）对高水平男子短跑运动员在垂直和水平方向上的下肢爆发力影响效果，并进一步揭示PAP的相关解释机制，以期为运动员的赛前热身活动和日常训练提供借鉴。研究方法：1）研究一通过Meta分析的方法量化基于拉长-缩短周期（SSC）练习的PAP对垂直跳和加速跑能力的影响效果；2）研究二和研究三以Meta分析结果为实验设计依据，通过随机交叉实验法采用Philips红外体温枪、GE-超声诊断仪、Delsys无线肌电测试仪、MyotonPRO肌肉功能测试仪、Kistler三维测力台、Kistler KiSprint数字起跑器、OptoJump运动系统和Witty光电计时等设备，分别在PAP诱导练习前后采集运动员的额温和股直肌温度、股直肌羽状角、肌肉募集特征（均方根振幅RMS和平均波谱功率MPF）、神经疲劳特征（电-机械延迟EMD）、下肢肌肉-肌腱刚度、垂直跳（CMJ）、起跑和20m加速跑（0～5m、0～10m和0～20m分段）成绩及相关运动力学数据。研究结果：1）Meta分析研究发现，基于SSC形式的PAP诱导练习后4～7min和8～12min，随后CMJ（ES = 0.31和0.39）和加速跑（ES = -0.22和-0.31）表现显著提升；然而在恢复时间为0～3min或≥15min时，PAP诱导练习对CMJ和加速跑无显著影响；2）实验研究发现，在无负重跳深（DJ）和20%体重负重跳深（WDJ）诱导练习后4min和8min时，运动员CMJ、起跑和加速跑表现均显著提升；同时肌电RMS和MPF显著提升，股直肌、腓肠肌和肌腱刚度显著提升，股直肌羽状角显著减小；3）WDJ能显著提升运动员平均步长，而DJ可显著提升运动员平均步频，与DJ相比，WDJ练习能更大程度提升股二头肌刚度。研究结论：1）恢复时间在4～8min时，是基于跳深形式的PAP诱导练习的最佳恢复时间，在这一时间段能最有效地提升运动员随后CMJ、起跑和加速跑能力；2）羽状角的减小、高阶运动单位募集的增加以及下肢肌肉-肌腱刚度的增加是共同解释PAP现象的适应机制；3）负重WDJ练习能更大程度改变股后肌群发力水平，而无负重DJ练习能促进神经冲动水平来急性提高随后CMJ、起跑和加速跑表现。研究创新：1）确定了基于不同负重形式的跳深练习对诱导最佳PAP的恢复时间；2）揭示了下肢单个肌群和肌腱刚度对调节PAP效果的贡献，并确定了羽状角减小、高阶运动单位募集和肌肉-肌腱刚度增加是共同解释PAP的适应性机制。

Purpose: To explore the acute effect of drop jump based PAP conditioning exercises on the vertical and horizontal lower limb explosive power performance of elite male sprinters, and further to reveal the relevant explanation mechanism of PAP, so as to providing a reference for athletes' warm-up program before competition and daily training.Methods: 1) In Study 1, the acute effect of the SSC-based PAP conditioning exercises on vertical jump and sprint acceleration was quantified by Meta-analysis; 2) In Study 2 and Study 3, a randomized crossover experiment was designed based on the results of meta-analysis in Study 1. The Philips infrared thermometer, GE-ultrasound diagnostic apparatus, Delsys wireless electromyography, MyotonPRO muscle function monitor, Kistler force plate, Kistler KiSprint, OptoJump, and Witty photoelectric timing equipment was used to measure the athlete's forehead temperature and rectus femoris temperature, rectus femoris feather angle, muscle recruitment characteristics (Root Mean Square, RMS; Mean Pectral Power, MPF), neural fatigue characteristics (electromechanical delay, EMD), lower limb muscle-tendon stiffness, countermovement jump (CMJ), sprint start and 20m acceleration (0-5m, 0-10m and 0-20m segments), and related kinematics data before and after the SSC-based PAP conditioning exercise.Results: 1) Meta-analysis found that, 4-7 and 8-12minutes after the SSC-based PAP conditioning exercises is the optimal recovery time for improving the subsequent CMJ (ES = 0.3 and 0.39) and sprinting acceleration (ES = -0.22 and -0.31) performance; When the recovery time is 0-3min, or 15min and above, PAP conditioning exercise has no significant effect on CMJ and sprinting acceleration performance; 2) The results of the experimental research indicated that, 4min and 8min after the DJ and WDJ conditioning exercises, the athletes' CMJ, sprinting start, and sprinting acceleration (0-5, 0-10 and 0-20m) performance were significantly improved; at the same time, the RMS and MPF were significantly improved, the stiffness of rectus femoris, gastrocnemius and tendon stiffness were significantly improved, and the pinnation angle of rectus femoris was significantly reduced; 3) WDJ can significantly increase the average step length of athletes, while DJ can significantly increase the average step frequency of athletes. Compared with DJ, WDJ exercises can increase the stiffness of the biceps femoris to a greater extent.Conclusions: 1) 4-8 minutes after the SSC-based PAP conditioning exercises is the optimal recovery time for improving the subsequent CMJ, sprinting start and acceleration performance; 2) The decrease in pinnate angle, the increase in recruitment of higher-order motor units, and the increase in lower limb muscle-tendon stiffness are the adaptive mechanisms that jointly explain the PAP phenomenon; 3) Weight-bearing WDJ exercises can greatly change the strength level of the posterior femoral muscles, while non-weight-bearing DJ exercises can promote the level of nerve impulse to acutely improve the subsequent CMJ, starting and sprint acceleration performance.Innovations: 1) Determined the recovery time of polymetric-based PAP conditioning exercises for inducing the best PAP effect; 2) Revealed the contribution of individual muscle and tendon stiffness of the lower limbs to the PAP phenomenon, and further determine the decrease of the pinnation angle, the recruitment of higher-order motor units, and the increase of muscle-tendon stiffness are the adaptive mechanisms of PAP.