短期增補羥基檸檬酸對耐力性運動表現之影響

Effect of short-term (-)-hydroxycitric acid supplementation on endurance exercise performance

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，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±6.4cm；體重：67.4±5.9kg）與P組（纖維素，2.5g／day，n=8；年齡：21.7±1.7歲；身高：173.3±4.2cm；體重：66.6±7.7kg）。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。此測驗包括10分鐘的低強度（40%V.O2max）與10分鐘的高強度（80%V.O2max）耐力性運動，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：不論是在增補前或增補後，H組與P組之間僅有碳水化合物氧化率達到顯著差異（p<.05），而身體組成、呼吸交換率、脂肪氧化率與運動表現皆未達顯著水準（p>.05）；儘管如此，H組在增補後的肌肉重、去脂體重、脂肪氧化率與運動表現皆顯著高於增補前，且呼吸交換率與碳水化合物氧化率在低強度耐力性運動中顯著比增補前降低（p<.05）。結論：短期增補羥基檸檬酸有助於減緩低強度運動時碳水化合物的氧化。

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 subjects performed an incremental endurance exercise test. The incremental endurance exercise test included 10-min mild (40%V.O2max) and 10-min heavy (80%V.O2max) exercises. The slope of treadmill was increased two degrees every three minutes till volitional exhaustion. Body composition was measured by bioelectrical impedance analyzer. Results: There were not different in body composition, respiratory exchange rate (RER), fat oxidation and exercise performance between the H group and P group (p> .05), but there were significant differences in carbohydrate oxidation (CHO oxidation) between the H group and P group (p< .05). However, muscle mass, lean body mass, fat oxidation and exercise performance were significantly increased after supplementation, and the RER and CHO oxidation were significantly decreased in H group during the mild endurance exercise(p< .05). Conclusion: Short-term HCA supplementation could decrease the CHO oxidation during the lower intensity endurance exercise.