Carbohydrate supplementation attenuates muscle glycogen loss during acute bouts of resistance exercise

• Published in: International journal of sport nutrition and exercise metabolism Vol. 10; no. 3; p. 326
• Main Authors: Haff, G G, Koch, A J, Potteiger, J A, Kuphal, K E, Magee, L M, Green, S B, Jakicic, J J
• Format: Journal Article
• Language: English
• Published: United States 01.09.2000
• Subjects: Adult; Blood Glucose - metabolism; Cross-Over Studies; Dietary Carbohydrates - pharmacology; Double-Blind Method; Exercise - physiology; Fatty Acids, Nonesterified - metabolism; Glycogen - metabolism; Humans; Lactic Acid - metabolism; Male; Muscle, Skeletal - drug effects; Muscle, Skeletal - metabolism
• ISSN: 1526-484X
• DOI: 10.1123/ijsnem.10.3.326

The effects of carbohydrate (CHO) supplementation on muscle glycogen and resistance exercise performance were examined with eight highly resistance trained males (mean +/- SEM, age: 24.3 +/- 1.1 years, height: 171.9 +/- 2.0 cm, body mass: 85.7 +/- 3.5 kg; experience 9.9 +/- 2.0 years). Subjects participated in a randomized, double blind protocol with testing sessions separated by 7 days. Testing consisted of an initial isokinetic leg exercise before and after an isotonic resistance exercise (IRT) session consisting of 3 leg exercises lasting approximately 39 min. Subjects consumed a CHO (1.0 g CHO.kg body mass(-1)) or placebo treatment (PLC), prior to and every 10-min (0.5 g CHO.kg body mass(-1)) during the IRT. Muscle tissue was obtained from the m vastus lateralis after a supine rest (REST) immediately after the initial isokinetic test (POST-ISO) and immediately after the IRT (POST-IRT). The CHO treatment elicited significantly less muscle glycogen degradation from the POST-ISO to POST-IRT (126.9 +/- 6.5 to 109.7 +/- 7.1 mmol.kg wet weight(-1)) compared to PLC (121.4 +/- 8.1 to 88.3 +/- 6. 0 mmol.kg wet weight(-1)). There were no differences in isokinetic performance between the treatments. The results of this investigation indicate that the consumption of a CHO beverage can attenuate the decrease in muscle glycogen associated with isotonic resistance exercise but does not enhance the performance of isokinetic leg exercise.