Erickson M A, Schwarzkopf R J, McKenzie R D
Movement Science Laboratory, Montana State University, Bozeman 59717.
Med Sci Sports Exerc. 1987 Dec;19(6):579-83.
Five competitive cyclists were used to determine the effects of fluid intake (16 ml.kg-1) consisting of: (i) non-nutrient control (CON); (ii) fructose (1 g.kg-1) before exercise (FRU); (iii) caffeine (5 mg.kg-1) before exercise (CAF); (iv) glucose (1 g.kg-1) during exercise (GLU); and (v) fructose/caffeine before and glucose during exercise (CFG) on blood glucose, free fatty acids, muscle glycogen, and other parameters. Exercise consisted of 90 min of cycling at 65 to 70% VO2max. Following exercise, blood glucose was found to be significantly (P less than 0.05) higher for CFG and GLU (117 and 109 mg%) compared to CON, CAF, and FRU (92, 89, and 86 mg%). Blood free fatty acids rose (P less than 0.05) further for CON (1,336), CAF (1,126), and FRU (1,034) over CFG (737) and GLU (714 mumol.l-1). Muscle glycogen utilization was greater (P less than 0.05) for CON (91) vs CAF (63) and GLU (62 mumol/g-1 wet muscle weight). It was concluded that GLU and CAF decrease muscle glycogen utilization, FRU is likely to cause gastric upset, and ingestion of multiple substances produces the greatest variability in muscle glycogen utilization and may provide added endurance benefits in some individuals.
选取了五名有竞争力的自行车运动员，以确定摄入以下几种液体（16毫升/千克体重）的影响：（i）无营养对照物（CON）；（ii）运动前摄入果糖（1克/千克体重）（FRU）；（iii）运动前摄入咖啡因（5毫克/千克体重）（CAF）；（iv）运动期间摄入葡萄糖（1克/千克体重）（GLU）；以及（v）运动前摄入果糖/咖啡因且运动期间摄入葡萄糖（CFG）对血糖、游离脂肪酸、肌肉糖原及其他参数的影响。运动包括在65%至70%最大摄氧量下骑行90分钟。运动后发现，与CON、CAF和FRU（分别为92、89和86毫克%）相比，CFG组和GLU组的血糖显著更高（P<0.05）（分别为117和109毫克%）。与CFG组（737）和GLU组（714微摩尔/升）相比，CON组（1336）、CAF组（1126）和FRU组（1034）的血液游离脂肪酸进一步升高（P<0.05）。CON组（91）的肌肉糖原利用率高于CAF组（63）和GLU组（62微摩尔/克湿肌肉重量）（P<0.05）。得出的结论是，GLU和CAF可降低肌肉糖原利用率，FRU可能会引起胃部不适，摄入多种物质会导致肌肉糖原利用率的最大变异性，并且可能会为某些个体带来额外的耐力益处。
