目的：探討不同最大自主等長收縮（maximal voluntary isometric contractions, MVICs）時間 誘發活化後增能作用（postactivation potentiation, PAP）後，對仰臥推擲表現之影響。方法：12 名男性擲部選手參與此重複量數且交叉設計之實驗。實驗處理包括3組3秒仰臥推舉MVICs處理 （3 MVICs）、3組5秒仰臥推舉MVICs處理（5 MVICs）與控制處理（CON）。記錄推擲高度 與槓鈴騰空時間，並分析推擲高度以及力量與功率之峰值。結果：不論是3 MVICs、5 MVICs或 是CON，推擲高度於後測各時間點皆顯著低於前測平均值，功率峰值於第4分鐘、第8分鐘與後 測平均值，皆顯著低於前測平均值。然而，力量峰值於後測各時間點與前測平均值均無顯著差 異。結論：即使給予較長的組間恢復時間，3 MVICs與5 MVICs產生肌肉疲勞的程度可能高於誘 發PAP的程度，進而無法提升訓練良好運動員的上肢爆發力表現。

Purpose: The aim of this study was to investigate the postactivation potentiation (PAP) effects induced by different maximal voluntary isometric contractions (MVICs) times on the bench press throw (BPT) performance. Methods: Twelve male throwing athletes volunteered to participate in this repeated measures and crossover designed study. All participants performed 3 different treatments, included 3 × 3-s MVICs (3MVICs), 3 × 5-s MVICs (5MVICs), and control (CON). The throwing height (TH) and flying time of barbell during BPT were measured to further analyze the TH, peak force (PF) and peak power output (PPO). Results: Regardless of 3 MVICs, 5 MVICs or CON treatment, the TH at 4-min, 8-min, 12-min, and average value after treatment were significantly lower than the average value at pre-test. Regardless of the treatments, PPO at 4-min, 8-min, and average value after treatment were significantly lower than the average value at pre-test. However, regardless of the treatments, PF at 4-min, 8-min, 12-min, and average value after treatment were not significantly different from average value at pre-test. Conclusion: Although the long rest intervals between sets were arranged, the effects of 3 MVICs and 5 MVICs treatments on muscle fatigue might overtake the PAP, thus could not improve the explosive performance in upper body in well-trained athletes.