Effect of green tea extract supplementation on glycogen replenishment in exercised human skeletal muscle. Issue 10 (20th June 2017)

• Record Type: Journal Article
• Authors: Tsai, Tsen-Wei; Chang, Chia-Chen; Liao, Su-Fen; Liao, Yi-Hung; Hou, Chien-Wen; Tsao, Jung-Piao; Cheng, I.-Shiung
• Is Part Of: British journal of nutrition. Volume 117:Issue 10(2017)
• Page Start: 1343
• Page End: 1350
• Publication Date: 2017-06-20
• Subjects: Ergogenic aids, -- Glycogen synthesis, -- Exercise, -- Green tea extract; Nutrition -- Periodicals; 572.4
• DOI: 10.1017/S0007114517001374
• Languages: English
• ISSNs: 0007-1145

Abstract

Abstract: The purpose of this study was to investigate the effects of 8-week green tea extract (GTE) supplementation on promoting postexercise muscle glycogen resynthesis and systemic energy substrate utilisation in young college students. A total of eight healthy male participants (age: 22·0 (se 1·0) years, BMI: 24·2 (se 0·7) kg/m 2, VO2max : 43·2 (se 2·4) ml/kg per min) participated in this study. GTE (500 mg/d for 8 weeks) was compared with placebo in participants in a double-blind/placebo-controlled and crossover study design with an 8-week washout period. Thereafter, all participants performed a 60-min cycling exercise (75 % VO2max ) and consumed a carbohydrate-enriched meal immediately after exercise. Vastus lateralis muscle samples were collected immediately (0 h) and 3 h after exercise, and blood and gaseous samples were collected during the 3-h postexercise recovery period. An 8-week oral GTE supplementation had no effects on further promoting muscle glycogen resynthesis in exercised human skeletal muscle, but the exercise-induced muscle GLUT type 4 (GLUT4) protein content was greater in the GTE supplementation trial ( P <0·05). We observed that, during the postexercise recovery period, GTE supplementation elicited an increase in energy reliance on fat oxidation compared with the placebo trial ( P <0·05), although there were no differences in blood glucose and insulin responses between the two trials. In summary, 8-week oral GTE supplementation increases postexercise systemic fat oxidation and exercise-induced muscle GLUT4 protein content in response to an acute bout of endurance exercise. However, GTE supplementation has no further benefit on promoting muscle glycogen resynthesis during the postexercise period.