目的:本研究的目的是量化与等热量CHO饮料相比,向碳水化合物(CHO)饮料中添加海藻酸钠和果胶对外源性葡萄糖(ExGluc)氧化速率的影响。
方法:熟悉后,八名训练有素的耐力运动员进行了四次长时间跑步(105分钟;VO2max的71±4%),同时每15分钟摄入175mL的一种实验饮料。按照随机顺序,参与者消耗了70g.h-1的麦芽糊精和果糖(10%CHO;NORM),70g.h-1的麦芽糊精,果糖,海藻酸钠,和果胶(10%CHO;ENCAP),180g.h-1麦芽糊精,果糖,海藻酸钠,和果胶(26%CHO;HiENCAP),或水(WAT)。所有CHO饮料的麦芽糊精:果糖比为1:0.7,并含有1.5g.L-1氯化钠。总底物氧化,ExGluc氧化速率,血糖,血乳酸,血清非酯化脂肪酸(NEFA)浓度,每15分钟测量一次RPE。每30分钟参与者提供有关其胃肠道不适(GID)的信息。
结果:NORM和ENCAP之间的ExGluc氧化峰没有显着差异(分别为0.63±0.07和0.64±0.11g.min-1;p>0.5),均显著低于HiENCAP(1.13±0.13g.min-1,p<0.01)。从60和75分钟,NORM和HiENCAP都显示出比WAT更高的总CHO氧化,分别,直到锻炼结束,CHO试验之间没有差异。在最初的60分钟内,WAT的血糖明显低于NORM和HiENCAP,但是CHO饮料之间没有发现差异。ENCAP和HiENCAP在60-105分钟内均显示出比WAT更高的血糖浓度,ENCAP显著高于HiENCAP。试验之间报告的GID症状没有显着差异。
结论:在中等摄食率下(即,70g.h-1),与等热量CHO饮料相比,添加海藻酸钠和果胶不会影响ExGluc的氧化速率。在非常高的摄取率下(即,180g.h-1),ExGluc氧化的高速率与文献一致。
OBJECTIVE: The purpose of this study is to quantify the effect of adding sodium alginate and pectin to a carbohydrate (CHO) beverage on exogenous glucose (ExGluc) oxidation rate compared with an isocaloric CHO beverage.
METHODS: Following familiarization, eight well-trained endurance athletes performed four bouts of prolonged running (105 min; 71 ± 4% of VO2max) while ingesting 175 mL of one of the experimental beverages every 15 min. In randomized order, participants consumed either 70 g.h-1 of maltodextrin and fructose (10% CHO; NORM), 70 g.h-1 of maltodextrin, fructose, sodium alginate, and pectin (10% CHO; ENCAP), 180 g.h-1 of maltodextrin, fructose, sodium alginate, and pectin (26% CHO; HiENCAP), or water (WAT). All CHO beverages had a maltodextrin:fructose ratio of 1:0.7 and contained 1.5 g.L-1 of sodium chloride. Total substrate oxidation, ExGluc oxidation rate, blood glucose, blood lactate, serum non-esterified fatty acid (NEFA) concentration, and RPE were measured for every 15 min. Every 30 min participants provided information regarding their gastrointestinal discomfort (GID).
RESULTS: There was no significant difference in peak ExGluc oxidation between NORM and ENCAP (0.63 ± 0.07 and 0.64 ± 0.11 g.min-1, respectively; p > 0.5), both of which were significantly lower than HiENCAP (1.13 ± 0.13 g.min-1, p < 0.01). Both NORM and HiENCAP demonstrated higher total CHO oxidation than WAT from 60 and 75 min, respectively, until the end of exercise, with no differences between CHO trials. During the first 60 min, blood glucose was significantly lower in WAT compared with NORM and HiENCAP, but no differences were found between CHO beverages. Both ENCAP and HiENCAP demonstrated a higher blood glucose concentration from 60-105 min than WAT, and ENCAP was significantly higher than HiENCAP. There were no significant differences in reported GID symptoms between the trials.
CONCLUSIONS: At moderate ingestion rates (i.e., 70 g.h-1), the addition of sodium alginate and pectin did not influence the ExGluc oxidation rate compared with an isocaloric CHO beverage. At very high ingestion rates (i.e., 180 g.h-1), high rates of ExGluc oxidation were achieved in line with the literature.