Effect of Eight Weeks Oral Green Tea Extracts Supplementation on Energy Metabolism Involved in Glycogen Synthesis and Intramuscular Triglyceride in Exercised Human Skeletal Muscle

• Main Authors: Lai, Hsin-Tung, 賴信同
• Other Authors: Cheng, I-Shiung
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/u8k944

碩士 === 國立臺中教育大學 === 體育學系碩士班 === 103 === Previous studies showed that green tea extracts (GTE) are able to reduce body fat mass in mice and humans. Skeletal muscle is the most important tissue involved in the regulation of glucose and fatty acids metabolism in human. Glycogen content and Intramyocellular Triglyceride (IMGT) in skeletal muscle influences the individuals’ endurance performance. The mechanism behind this phenomenon and GTE impact on metabolic consequences in human skeletal muscle remains unclear. Therefore, the present study investigated whether eight weeks oral GTE supplementation enhanced fatty acid oxidation and attenuated glucose utilization resulting in enough glycogen reserves in exercised human skeletal muscle. Eight healthy volunteer subjects (average age 21.9 ± 0.77 years old) were given 500mg of GTE per day for consecutive eight weeks. Before and after GTE supplementation, every subject was asked to perform cycling exercise for 60 minutes at 75% VO2 max and consumed a carbohydrate meal (2 g carbohydrate/kg body weight, 80 % carbohydrate, 8 % fat, 12 % protein) immediately after cycling exercise. Biopsied muscle samples were taken from vastus lateralis immediately and 3-h following exercise. We found significantly increased muscle glycogen synthesis after GTE administration compared to pre-GTE supplement under condition after a single bout of exercise ( p < .05). Muscle GLUT4 protein expression was significantly elevated immediately after exercise in GTE Administration. However, IMTG level was not significantly altered with GTE administration. In contrast, evidences from our previous lab data about gaseous exchanges analyses showed that GTE had advantage effects on enhancing the fat oxidation during exercise recovery period after GTE supplementation. The phenomenon of IMTG and gaseous exchange after GTE supplementation implied that GTE enhanced fat oxidation not IMTG during exercise recovery period. However, The present study suggested that eight weeks oral GTE supplementation can be used as ergogenic aids, evidences from our results showed the beneficial effect of GTE on glycogen synthesis in exercised human skeletal muscle.