Publication:

急性低氧環境下攝取咖啡因對脂肪氧化的影響

過去的研究已證實於常氧環境下攝取咖啡因可提升脂肪代謝率，減少碳水化合物消耗，有助提升耐力運動表現。因此本研究目的為探討在低氧環境下攝取咖啡因對脂肪代謝的影響，並討論不同高、低攝氧量受試者，對增補劑的反應。以22名健康男性為研究對象，每位受試者皆需完成四組漸增性腳踏車運動至衰竭的測試，均於低氧環境下進行；運動前60分鐘攝取增補劑，分別為咖啡因組( C, 6 mg/ kg )、碳水化合物組 ( G, 75 g )、咖啡因+碳水化合物組( C+G )和安慰劑組( P )，並以攜帶式氣體分析儀，採集安靜時和運動期間每階段氣體；以0~15分鐘前的氣體為時間對應點，並依照圖形的不同計算0以上之三角型或梯型面積。結果發現脂肪氧化曲線下面積C組顯著高於C+G組（p =0.009）及G組( p=0.007 )；碳水化合物氧化的曲線下面積C組顯著低於C+G組（p =0.016）及G組（p=0.001）；運動表現C+G組顯著高於P組（p=0.005）和G組（p =0.003）兩組（平均為P組1159±156秒；C組1195±156秒；C+G組1215±177秒；G組1165±187秒）。研究結果顯示低氧下攝取咖啡因能有效提升脂肪氧化率，並抑制碳水化合物氧化率。

Ingestion of caffeine before exercise increased fat oxidation and reduced carbohydrate oxidation in normoxia condition. The present study was to investigate the effect of ingestion caffeine on fat oxidation in acute hypoxia environment. Twenty-two health, active subjects participated in study. Subjects completed 4 experimental trials: caffeine (C, 6mg/kg), carbohydrate (G, glucose 75g), caffeine+carbohydrate (C+G) and placebo (P). Subjects ingested the supplementation 60 min before performed a graded exercise to exhaustion in a hypoxia chamber (~15%O2). Expired gas samples were collected for calculation the rate of carbohydrate and fat oxidation. The results showed that rate of fat oxidation were higher in C than C+G（p=0.009） and G（p=0.007）. The rate of carbohydrate oxidation were significantly lower in C than C+G （p=0.016） and G （p=0.001）. The exercise time were significantly higher in C+G than P （p=0.005） and G （p=0.003）（P:1159±156 sec; C:1195±156 sec; C+G:1215±177sec; G:1165±187sec）. The current data suggested ingestion of caffeine increased fat oxidation and reduced carbohydrate oxidation in acute hypoxia condition