Effects of Post-Exercise Carbohydrate and Carnitine Supplementation on Muscle Glycogen Synthesis in Human Skeletal Muscle

• Main Authors: Chiou-Tain Lin, 林秋騰
• Other Authors: Shiang-Ju Liu
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/19548560093984749934

碩士 === 國立臺中教育大學 === 體育學系碩士班 === 99 === Effects of post-exercise carnitine supplementation on glycogen synthesis in human skeletal muscle Abstract Carnitine is required for mitochondrial fatty acid oxidation, and thus it is reasonable to speculate that an increase in carnitine content might increase the rate of fatty acid oxidation. High carnitine content in resting skeletal muscle attenuated glycolysis pathway, enhanced muscle glycogen synthesis through the increase in fat oxidation. Whether similar effects in glycogen synthesis was existed in human study during post-exercise recovery after carnitine supplementation immediately after a single bout of exercise is not known currently. In this study we found that post-exercise catnitine supplementation enhanced muscle glycogen synthesis effectly, evidenced directly by glycogen concentration in human skeletal muscle. Seven healthy male subjects (aged: 20.07 ± 0.31 years old) completed two treatments with either carnitine or placebo supplement, separated at least 7 days. On the day of the experiment, subjects followed an overnight fasting, then accepted a single bout of bicycle ergometer exercise with 70% VO2 peak for 60 minutes and consumed a high carbohydrate meal with 2000 mg carnitine or placebo immediately after exercise. During 3 hours exercise recovery, biopsy muscle samples on the deeply vastus lateralis were obtained for muscle glycogen analyzing. Furthermore, blood samples were collected for glucose and insulin analyzing every 30 minutes. The expired gas samples were collected every 60 minutes each with 10 minutes duration for 3 hours exercise recovery for respiratory exchange ratio (RER), carbohydrate oxidation rate, and fat oxidation rate. The results showed that post-exercise carbohydrate and carnitine supplementation could increase muscle glycogen synthesis, decrease insulin secretion at 120 min、150 min and decrease RER at 180 min compared with carbohydrate supplementation alone (p＜.05) . The blood glucose levels, fat oxidation rate, and carbohydrate oxidation rate in carnitine were not significantly different compared to those in placebo during exercise recovery (p＜.05) . The conclusion of this study was that post-exercise carbohydrate and carnitine supplementation could benefit the effect of muscle glycogen synthesis compared with carbohydrate supplementation alone. Key words: carnitine, muscle glycogen, ergogenic aids, recovery