目的：探討 4mmol/l 速度間歇訓練以固定時間 40 秒 (time determinant, TD) 與回到 2mmol/l 心跳率 (heart rate determinant, HRD) 休息方式對於中長距離選手的影響。方法： 受試者為 8 名青少年男性中長距離選手，年齡 16.6 ± 0.5 歲、身高 171.1 ± 3.8 公分、體重 61.3 ± 6.0 公斤。受試者先接受漸增強度跑步測驗後一週，以平衡次序接受不同休息方式的 4mmol 速度 (3.8 ± 0.3 m/s) 間歇訓練 (2 sets × 5 reptitions × 3 min)，兩次訓練至少間隔 48 小時。記錄訓練中第 1、3、5、6、8、10 次 (reptition, rep)後及訓練結束後第 3、5 分鐘的 血乳酸 (blood lactate, La) 與心跳率 (heart rate, HR)。測驗結果使用相依樣本二因子變異數 分析進行比較，顯著水準訂為 p<.05。結果：不同休息方式對於訓練中 La 有交互作用 (F=10.52, p <.05)，而 HR 則無 (p >.05)；TD 訓練後第 3 分鐘的 La 顯著高於 HRD，但 HR 無顯著差異。TD 時，rep 3 (3.09 ± 0.16 mmol/l) 及 rep 8 (2.86 ± 0.17 mmol/l) 的 La 與 rep 1 (3.93 ± 0.14 mmol/l) 有顯著差異 (p<.05) ，HR 隨著反覆逐漸上升；HRD 時，rep 5、rep 8、 rep 10 (2.79 ± 0.16-3.51 ± 0.13 mmol/l) 的 La 顯著低於 rep1 (3.85 ± 0.11 mmol/l)，而 HR 亦 隨著反覆而上升。結論：休息方式會影響中長距離選手在單次 4mmol/l 速度間歇訓練中的 肌肉能量代謝，但對於體循環的改變影響不大。

Purpose: To investigate the effect of different rest strategies which were constant time (40 sec, TD) and back to 2mmol/l heart rate (HRD) during the 4mmol/l speed interval training on middle and long distance runners. Methods: Eight male adolescent middle and long distance runners (age: 16.6 ± 0.5 yrs, height: 171.1 ± 3.8 cm, weight: 61.3 ± 6.0 kg) were recruited in this study. Subjects were accepted to increment treadmill tests and after one week, two different rest strategies were applied to 4mmol/l speed (3.8 ± 0.3 m/s) interval running (2 sets×5 reps×3 min) in counter balance order with 48 hours separated. Blood lactate (La) and heart rate (HR) were recorded at 1st, 3rd, 5th, 6th, 8th, and 10th repetition and 3rd, 5th minute after training. Using two-way ANOVA with repeat measures to compare inter- and intra- La and HR during different rest strategies. The significant level was set at p<.05. Results: Interaction was showed on La at different rest strategies during training (F=10.52， p<.05), but it wasn’t on HR (p>.05). After training, La at the 3rd minute of TD was significant higher than HRD, but no difference in HR was found. During the TD, La at rep3 (3.09 ± 0.16 mmol/l) and rep8 (2.86 ± 0.17 mmol/l) were significantly different from rep1 (3.93 ± 0.14 mmol/l) (p<.05) and HR were increased with repetitions (p<.05). During the HRD, the La of rep5, rep8 and rep10 (2.79 ± 0.16-3.51 ± 0.13 mmol/l) were significant lower than rep1 (3.85 ± 0.11 mmol/l) and HR increased with repetitions, too (p<.05). Conclusion: Different rest strategies may affect metabolism of muscle during 4mmol/l speed interval training but no significant effect on circulation.