目的: 探討長跑選手進行間歇訓練時，不同休息時間對於跑步速度、心跳率及運動後血乳酸的影響，並比較兩種間歇訓練的自選休息時間差異，以提供間歇訓練休息時間之建議。方法: 以國內8名優秀長跑選手 (6名男性、2名女性，年齡24.8±5.8歲、身高168.8±7.9公分、體重57.5±6.5公斤、5000公尺成績16.9±2.0 分鐘) 為受試對象，利用跑步機與Cosmed Quark CPET氣體分析系統進行前測，以取得VO2max、vVO2max及HRmax等相關數據。依平衡次序原則，將受試者分配成3組，每組皆進行4週，每週一次之1200M×5、跑步強度為vVO2max之測驗，間歇休息時間隨機分配為1、2及4分鐘及自選休息時間，共四次跑步漸歇訓練；另外再進行一次800Mx8、跑步強度略高於vVO2max、自選休息時間的間歇訓練，以比較不同距離間歇訓練自選休息時間之差異。結果: 間歇訓練時以1分鐘、2分鐘、4分鐘、自選休息時間 (1.94±0.68分鐘)，各趟次1200m的跑步運動時間、運動期心跳率及運動後血乳酸濃度皆沒有顯著差異，但休息一分鐘之休息期心跳率顯著高於其他休息時間。800mx8自選休息時間 (1.69±0.26分鐘) 間歇運動後血乳酸濃度顯著高於1200M×5自選休息時間。結論: 依據跑步時間、運動期心跳率、血乳酸濃度來看，進行1200 m×5跑步間歇訓練時，1-4分鐘休息時間具備相同的影響。1分鐘的休息時間會造成休息期心跳率偏高。 Purpose: The aim of this study is to investigate impact of training effect to different rest duration during interval training. And compare the difference of two self- selected rest durations to make suggestion for the runners who intents to do interval training. Method: 8 elite runners (6 male and 2 female, age 24.8±5.8, height 168.8±7.9cm, weight57.5±6.5kg, 5000M 16.9±2.0min) performed treadmill test to collect the VO2max, vVO2max and HRmax data as the reference of interval training intensity. All participants were assigned to 3 groups. Each group performed 4 sessions of 1200M x 5 rounds by vVO2max and 1 session of 800M x 8 slightly higher intensity than vVO2max of interval training on the track. The rest duration of each round was randomly assigned to each group by 1, 2 and 4 minutes in first 3 rounds of 1200Mx5. All participants performed the 4th session interval training by self-selected rest duration. The last session was 800Mx8 self-selected rest duration. Data was analyzed by One-way ANOVA, Repeated measure t test and Two-way ANOVA repeated measure to compare the maximum heart rate during running period, lowest heart rate during rest period, blood lactate at 3-5 minutes post exercise of each session and running time of each round of interval training in between different rest durations. The level of significance was set as .05. Result: The difference of 1200Mx5 running time, maximum heart rate during running period and blood lactate at 3-5 minutes post exercise of different rest duration 1 min, 2 min, 4 min and self-selected 1.94±0.68 min) were not significant. The lowest heart rate in 1 minute rest duration was significantly higher than other rest durations. The post exercise blood lactate of 800mx8 self-selected rest duration (1.69±0.26 min) was higher than 1200M×5 self-selected rest duration. Conclusion: According to running time, maximum heart rate during running period and blood lactate, the impact of 1-4 minutes rest duration would be same for1200 m×5 interval training. One minute rest duration for 1200Mx5 interval training would result in higher heart rate at rest duration.