- 期刊
排便對鐵人三項運動員耐力運動表現之影響
Effect of Bowel Evacuation on Endurance Performance in Triathletes
摘要
腸胃道已被發現對於健康有著重要的影響，而研究指出許多鐵人三項運動員曾經驗腸道不適而中斷訓練或比賽。儘管如此，還未有探討將腸胃道清空對耐力運動表現之研究。本研究目的為探討鐵人三項運動員補充氧化鎂幫助糞便排空對自由車耗竭耐力運動表現，同時觀察大腦前額葉及下腹腸道的血液分配情況。以13位鐵人三項運動員進行實驗，採平衡交叉設計，比較補充氧化鎂糞便排空與未排空狀態，進行自由車80%最大攝氧量耗竭運動測驗，兩試驗間隔1週以上，且在運動前90分鐘完成排便，檢測全程以近紅外線光譜記錄大腦前額葉與下腹腸道血液分配情況。研究結果顯示：13位受試者有10位耐力提升，3位耐力下降。觀察近紅外線光譜血液分配方面（相對於運動前的基礎值），大腦前額葉總血紅素，兩試驗皆顯著提升，運動初期兩試驗間達顯著差異；血氧飽和度指標，排空試驗比未排空下降趨勢更明顯。下腹腸道部分，總血紅素兩試驗皆顯著下降；血氧飽和度在運動過程（騎乘時間5%～65%），排空試驗顯著低於基礎值。本研究結論指出補充氧化鎂進行糞便排空無助於促進自由車耗竭運動表現，但是排便後運動初期大腦能獲得較多總血紅素分配。
並列摘要
The gastrointestinal tract has been recognized as having a significant impact on health. Studies have indicated that many triathletes have experienced gastrointestinal discomfort, leading to the interruption of their training or races. Nevertheless, there has been a paucity of research investigating the effects of gastrointestinal clearance on endurance performance. The purpose of this study was to examine the effects of magnesium oxide-induced bowel evacuation on the cycling endurance performance and blood allocation situation in the prefrontal cortex and the lower abdominal regions for triathletes. A total of 13 triathletes participated in the study. Cycling time to exhaustion was assessed at 80% maximal oxygen uptake (VO_(2max)) under magnesium oxide-induced bowel evacuation and non-evacuated conditions using a counterbalanced crossover design, separated by a week. Bowel evacuation was completed voluntarily in the morning, 90 minutes before the performance test. Near-Infrared spectroscopy (NIRS) measurement was employed to monitor homodynamic responses in the prefrontal cortex and lower abdominal intestine during cycling. Results revealed that: 10 of 13 participants showed improvement and 3 showed decreases in endurance. Observing blood allocation situation through NIRS (relative to baseline before exercise), the total hemoglobin concentration in the prefrontal cortex significantly increased in both trials, with significant differences between the two trials in the early stages of exercise. Oxygen saturation displayed a more pronounced decrease in the bowel evacuation trial compared to the non-evacuation trial. In the lower abdomen, the total hemoglobin concentration significantly decreased in both trials. During the exercise period (cycling time 5%-65%), the bowel evacuation trial showed significantly lower oxygen saturation than the baseline. We conclude that the supplementing with magnesium oxide for bowel evacuation does not improve performance in cycling endurance exercise. However, following bowel evacuation, there is an increased allocation of total hemoglobin to the brain during the early stages of exercise.