Abstract：
BACKGROUND: Post-activation performance enhancement (PAPE) is a physiological phenomenon that acutely improves voluntary muscular performance following a conditioning activity. A large and growing body of literature has investigated different strategies to induce a PAPE stimulus; however, little attention has been given to whether acute caffeine ingestion could augment the effect of PAPE on subsequent performance. This study evaluated the acute effects of caffeine ingestion and back squat conditioning activity on subsequent countermovement jump (CMJ) performance in female semi-professional volleyball players.
METHODS: Fourteen resistance-trained female volleyball players (26 ± 3 years) performed 3 different testing conditions in randomized order: where each ingested 6 mg/kg of caffeine (CAF) or placebo (PLAC) and performed a single set of back squats at 80%1RM until mean movement velocity dropped by 10% as the conditioning activity or a control (CTRL) condition where participants did not ingest any supplement and did not perform the conditioning activity. CMJ height was examined at baseline and in 2 min intervals until 10 min postconditioning activity. Furthermore, due to the wide inter-individual variation in optimal recovery time of PAPE response, the baseline and best post-conditioning activity performance were also analyzed.
RESULTS: The Friedman test revealed a significant difference in jump height within CTRL (p = 0.002) and CAF (p = 0.001) conditions, but no significant difference was found within the PAP condition. The post hoc showed a significant decrease in jump height in 8th min in CTRL condition (p = 0.022, effect size [ES] = -0.31), a significant increase in jump height in 2nd min in CAF condition (p = 0.013, ES = 0.3), without differences in PLAC condition in comparison to baseline values. Moreover, a significant jump height increases from baseline to best performance post conditioning activity value for CAF (p = 0.001, ES = 0.39) and PLAC (p = 0.001, ES = 0.3) condition, but no significant difference was found for the CTRL condition.
CONCLUSIONS: The single set of heavy-loaded back squats with controlled velocity used as a conditioning activity in the current study enhanced subsequent CMJ performance in female volleyball players with no additional effect of caffeine.
METHODS: Fourteen resistance-trained female volleyball players (26 ± 3 years) performed 3 different testing conditions in randomized order: where each ingested 6 mg/kg of caffeine (CAF) or placebo (PLAC) and performed a single set of back squats at 80%1RM until mean movement velocity dropped by 10% as the conditioning activity or a control (CTRL) condition where participants did not ingest any supplement and did not perform the conditioning activity. CMJ height was examined at baseline and in 2 min intervals until 10 min postconditioning activity. Furthermore, due to the wide inter-individual variation in optimal recovery time of PAPE response, the baseline and best post-conditioning activity performance were also analyzed.
RESULTS: The Friedman test revealed a significant difference in jump height within CTRL (p = 0.002) and CAF (p = 0.001) conditions, but no significant difference was found within the PAP condition. The post hoc showed a significant decrease in jump height in 8th min in CTRL condition (p = 0.022, effect size [ES] = -0.31), a significant increase in jump height in 2nd min in CAF condition (p = 0.013, ES = 0.3), without differences in PLAC condition in comparison to baseline values. Moreover, a significant jump height increases from baseline to best performance post conditioning activity value for CAF (p = 0.001, ES = 0.39) and PLAC (p = 0.001, ES = 0.3) condition, but no significant difference was found for the CTRL condition.
CONCLUSIONS: The single set of heavy-loaded back squats with controlled velocity used as a conditioning activity in the current study enhanced subsequent CMJ performance in female volleyball players with no additional effect of caffeine.
摘要：
背景：激活后表现增强（PAPE）是一种生理现象，可在调节活动后急剧改善随意的肌肉表现。越来越多的文献研究了诱导PAPE刺激的不同策略；然而，对于急性咖啡因摄入是否会增强PAPE对后续表现的影响，人们很少关注。这项研究评估了咖啡因摄入和后蹲调节活动对女性半职业排球运动员随后的反运动跳跃（CMJ）表现的急性影响。
方法：十四名抗阻训练的女排球运动员（26±3岁）以随机顺序进行了3种不同的测试条件：每个人摄入6mg/kg的咖啡因（CAF）或安慰剂（PLAC），并以80％1RM进行单组后深蹲，直到平均运动速度下降10％，因为条件活动或对照（CTRL）条件下参与者没有摄取任何补充活动也没有进行在基线和2分钟间隔内检查CMJ高度，直到10分钟后处理活动。此外，由于PAPE反应的最佳恢复时间的个体间差异很大，还分析了基线和最佳后处理活动表现.
结果：弗里德曼检验显示，在CTRL（p=0.002）和CAF（p=0.001）条件下，跳跃高度存在显着差异，但在PAP条件下没有发现显着差异。事后显示，在CTRL条件下，第8分钟的跳跃高度显着下降（p=0.022，效应大小[ES]=-0.31），CAF条件下第2分钟的跳跃高度显着增加（p=0.013，ES=0.3），与基线值相比，PLAC条件没有差异。此外，对于CAF（p=0.001，ES=0.39）和PLAC（p=0.001，ES=0.3）条件，从基线到最佳性能后调节活动值的显着跳跃高度增加，但CTRL条件没有发现显著差异。
结论：在目前的研究中，一组具有受控速度的重负荷后下蹲作为调节活动可增强女子排球运动员随后的CMJ表现，而咖啡因没有额外作用。
方法：十四名抗阻训练的女排球运动员（26±3岁）以随机顺序进行了3种不同的测试条件：每个人摄入6mg/kg的咖啡因（CAF）或安慰剂（PLAC），并以80％1RM进行单组后深蹲，直到平均运动速度下降10％，因为条件活动或对照（CTRL）条件下参与者没有摄取任何补充活动也没有进行在基线和2分钟间隔内检查CMJ高度，直到10分钟后处理活动。此外，由于PAPE反应的最佳恢复时间的个体间差异很大，还分析了基线和最佳后处理活动表现.
结果：弗里德曼检验显示，在CTRL（p=0.002）和CAF（p=0.001）条件下，跳跃高度存在显着差异，但在PAP条件下没有发现显着差异。事后显示，在CTRL条件下，第8分钟的跳跃高度显着下降（p=0.022，效应大小[ES]=-0.31），CAF条件下第2分钟的跳跃高度显着增加（p=0.013，ES=0.3），与基线值相比，PLAC条件没有差异。此外，对于CAF（p=0.001，ES=0.39）和PLAC（p=0.001，ES=0.3）条件，从基线到最佳性能后调节活动值的显着跳跃高度增加，但CTRL条件没有发现显著差异。
结论：在目前的研究中，一组具有受控速度的重负荷后下蹲作为调节活动可增强女子排球运动员随后的CMJ表现，而咖啡因没有额外作用。
