當人體從事各種運動項目時，隨著運動強度、時間甚至環境等因素，都會影響提供能量來源的比例，進而產生不同的結果及變化。而田徑中的800m及1500m運動員，所需具備的優異速度耐力與快速乳酸排除能力，則是需要經由訓練取得。而間歇訓練時所產生的乳酸值又高於反覆訓練，因此間歇訓練成為許多教練及運動員最為常用之訓練法。為瞭解中長跑運動員對於間歇訓練在強度的、生理適應等方面的結果，本研究以六位高中男子中長跑運動員為對象，實施五週的快速耐力間歇訓練，以前、後測的方式觀察乳酸閾值、心跳率、有氧與無氧能力、運動負荷等方面的變化並加以分析。結果發現，經過五週的閒歇訓練後，有氧閾值速度 (2mmol/l) 能力具有顯著差異，無氧閾值速度 (4mmol/l) 能力方面，前測與後測未達顯著差異，但在心跳率部分，Test-2較Test-1顯示有進步。乳酸於3.5 m/s與測試速度4.5 m/s前測與後測均達顯著差異。訓練負荷方面未達顯著差異。運動結束乳酸堆積在Set-1方面，第一週與第五週之第三分鐘達顯著差異。運動後恢復心跳率達顯著差異，最大負荷心跳率呈現下降之現象顯示耐力有進步。在無氧閾值與最大訓練負荷之關係方面，與200m最大訓練負荷有進步，而與300m最大訓練負荷則無明顯進步。總結以上，心跳率、基礎耐力及乳酸閾值之檢測，可做為協助提升選手之有氧與無氧耐力之能力訓練之依據。

　　Human performs exercises with different response, since the ratio of energy supply is changed depending on the intensity, duration of the exertion and environment condition. Elite 800 and 1500 meter runners particularly require higher speed endurance and faster lactic acid clearance abilities thought athletic training. Interval training has commonly been utilized by coaches and athletes while training, because it results in a higher lactate level as compare to repeat training. The purpose was to examine the effects of intensity and adaptation of interval training on distance runners. Six male distance runners from high school participated in this investigation as subjects. Interval training for speed endurance was performed for five weeks. The variations of lactate threshold, heart rate, aerobic and anaerobic abilities, and exercise load were examined and analyzed by administrating a pre-post test experiment. Result has shown a significant change in running speed at aerobic threshold (2 mmol/l) and not difference in running speed at anaerobic threshold (4 mmol/l) after the five-week interval training. An improved exercise heart rate was found from Test-1 to Test-2. Lactate was significantly different at 3.5 m/s and pre-post test at 4.5 m/s. Training load was not changed throughout the study. Lactate level was found significant difference in third min of recovery in the first and fifth of the training. Recovery heart rate was significantly lower following the training indicating an improvement of endurance. Maximum training load has improved 200 m and not change for 300 m run. In summary, monitoring of heart rate, endurance and lactate threshold during training provides valuable information to trainers and training load can be optimized to enhance aerobic and anaerobic endurance of the runners.