短期增補羥基檸檬酸對耐力性運動表現之影響

Abstract

目的：探討短期增補羥基檸檬酸對耐力運動表現的影響。方法： 17名健康男性自願參加以單盲為設計的實驗，且經由隨機分配為兩組：H組（羥基檸檬酸，2.5g/day，n=9，年齡：21.7±2.4歲，身高：177.9±6.4 cm，體重：67.4±5.9 kg）與P組（纖維素，2.5g/day，n=8，年齡：21.7±1.7歲，身高：173.3±4.2 cm，體重：66.6±7.7 kg）。連續五天增補羥基檸檬酸之前後，所有受試者須在原地跑步機上完成遞增負荷之耐力性運動測驗。遞增耐力性運動包括10分鐘的低強度（40%VO2max）與10分鐘的高強度（80%VO2max）運動，且隨後以每3分鐘增加2%坡度的負荷直到運動衰竭，並利用生物電阻法分析受試者身體組成的各項數據。結果：羥基檸檬酸組的體脂肪比增補前顯著降低（p< .05），而肌肉重與去脂體重則明顯比增補前增加（p < .05）。不論是在低強度或高強度下或增補前與增補後，羥基檸檬酸組與安慰劑組之間的心跳率、每分鐘攝氧量和運動後血乳酸值均無顯著差異存在（p > .05），然而，羥基檸檬酸組在低強度時的呼吸交換率與碳水化合物顯著降低，脂肪氧化顯著增加（p < .05），且衰竭時間也顯著地延長（p <.05）。結論：短期增補羥基檸檬酸不會影響低強度或高強度運動時的心跳率、每分鐘攝氧量與血乳酸值，儘管如此，羥基檸檬酸有助於促進脂肪氧化與延緩運動衰竭的時間。

Purpose: To investigate the effect of short-term (-)-hydroxycitric acid (HCA) supplementation on endurance exercise performance. Methods: Seventeen healthy males volunteered to participate in this single blind study, and were randomly divided in two groups: H group (HCA, 2.5 g/day, n = 9, age: 21.7±2.4 yrs, height: 177.9±6.4 cm, weight: 67.4±5.9 kg) and P group (cellulose, 2.5 g/day, n = 8, age: 21.7±1.7 yrs, height: 173.3±4.2 cm, weight: 66.6±7.7 kg). Before and after a 5-day load of HCA or placebo, all subjectsperformed an incremental endurance exercise test. The incremental endurance exercise test included 10-min mild (40%VO2max) and 10-min heavy (80%VO2max) exercises and then the slope of treadmill was increased two degrees every three minutes till volitional exhaustion. Body composition was measured by bioelectrical impedance analyzer. Results: There was a significantly decreased body fat only in H group (p< .05), and the lean body mass and muscle mass were significantly increased in H group after supplementation (p < .05). The heart rate (HR), oxygen intake and blood lactate had no significant differences between the H and P groups (p > .05), however, in the H group, the respiratory exchange rate (RER) and carbohydrate (CHO) oxidation were significantly decreased, and the fat oxidation was significantly increased (p < .05) during mild endurance exercise. In addition, the exhausting time was significantly extended in the H group (p< .05). Conclusion: Short-term HCA supplementation could not affect HR, oxygen intake and blood lactate either on the mild or the heavy endurance exercise, however, the fat oxidation and time to exhaustion during the endurance exercise would be improved by HCA.