title: Carbohydrate supplementation attenuates muscle glycogen loss during acute bouts of resistance exercise.
abstract: 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.
authors.affiliation: Exercise Physiology Laboratory, Appalachian State University, Boone, NC 28608, USA.
authors.forename: G G
authors.initials: GG
authors.lastname: Haff
authors.forename: A J
authors.initials: AJ
authors.lastname: Koch
authors.forename: J A
authors.initials: JA
authors.lastname: Potteiger
authors.forename: K E
authors.initials: KE
authors.lastname: Kuphal
authors.forename: L M
authors.initials: LM
authors.lastname: Magee
authors.forename: S B
authors.initials: SB
authors.lastname: Green
authors.forename: J J
authors.initials: JJ
authors.lastname: Jakicic
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D018592:Cross-Over Studies; D004040:Dietary Carbohydrates / Q000494:pharmacology*; D004311:Double-Blind Method; D015444:Exercise / Q000502:physiology*; D005230:Fatty Acids, Nonesterified / Q000378:metabolism; D006003:Glycogen / Q000378:metabolism*; D006801:Humans; D019344:Lactic Acid / Q000378:metabolism; D008297:Male; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000378:metabolism
chemical_list: D001786:Blood Glucose; D004040:Dietary Carbohydrates; D005230:Fatty Acids, Nonesterified; D019344:Lactic Acid; D006003:Glycogen