title: Postexercise carbohydrate-protein supplementation improves subsequent exercise performance and intracellular signaling for protein synthesis.
abstract: Postexercise carbohydrate-protein (CHO + PRO) supplementation has been proposed to improve recovery and subsequent endurance performance compared to CHO supplementation. This study compared the effects of a CHO + PRO supplement in the form of chocolate milk (CM), isocaloric CHO, and placebo (PLA) on recovery and subsequent exercise performance. Ten cyclists performed 3 trials, cycling 1.5 hours at 70% VO₂max plus 10 minutes of intervals. They ingested supplements immediately postexercise and 2 hours into a 4-hour recovery. Biopsies were performed at recovery minutes 0, 45, and 240 (R0, R45, REnd). Postrecovery, subjects performed a 40-km time trial (TT). The TT time was faster in CM than in CHO and in PLA (79.43 ± 2.11 vs. 85.74 ± 3.44 and 86.92 ± 3.28 minutes, p ≤ 0.05). Muscle glycogen resynthesis was higher in CM and in CHO than in PLA (23.58 and 30.58 vs. 7.05 μmol·g⁻¹ wet weight, p ≤ 0.05). The mammalian target of rapamycin phosphorylation was greater at R45 in CM than in CHO or in PLA (174.4 ± 36.3 vs. 131.3 ± 28.1 and 73.7 ± 7.8% standard, p ≤ 0.05) and at REnd in CM than in PLA (94.5 ± 9.9 vs. 69.1 ± 3.8%, p ≤ 0.05). rpS6 phosphorylation was greater in CM than in PLA at R45 (41.0 ± 8.3 vs. 15.3 ± 2.9%, p ≤ 0.05) and REnd (16.8 ± 2.8 vs. 8.4 ± 1.9%, p ≤ 0.05). FOXO3A phosphorylation was greater at R45 in CM and in CHO than in PLA (84.7 ± 6.7 and 85.4 ± 4.7 vs. 69.2 ± 5.5%, p ≤ 0.05). These results indicate that postexercise CM supplementation can improve subsequent exercise performance and provide a greater intracellular signaling stimulus for PRO synthesis compared to CHO and placebo.
authors.affiliation: Exercise Physiology and Metabolism Laboratory, Department of Kinesiology, University of Texas at Austin, Austin, Texas, USA.
authors.forename: Lisa
authors.initials: L
authors.lastname: Ferguson-Stegall
authors.forename: Erin L
authors.initials: EL
authors.lastname: McCleave
authors.forename: Zhenping
authors.initials: Z
authors.lastname: Ding
authors.forename: Phillip G
authors.initials: PG
authors.lastname: Doerner
authors.forename: Bei
authors.initials: B
authors.lastname: Wang
authors.forename: Yi-Hung
authors.initials: YH
authors.lastname: Liao
authors.forename: Lynne
authors.initials: L
authors.lastname: Kammer
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.forename: Jungyun
authors.initials: J
authors.lastname: Hwang
authors.forename: Benjamin M
authors.initials: BM
authors.lastname: Dessard
authors.forename: John L
authors.initials: JL
authors.lastname: Ivy
mesh_terms: D000293:Adolescent; D000328:Adult; D001707:Biopsy, Needle; D001774:Blood Chemical Analysis; D018592:Cross-Over Studies; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D004044:Dietary Proteins / Q000008:administration & dosage*; D019587:Dietary Supplements; D004311:Double-Blind Method; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test / Q000379:methods; D005260:Female; D006003:Glycogen / Q000378:metabolism; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism / Q000473:pathology; D010807:Physical Endurance / Q000187:drug effects* / Q000502:physiology; D005082:Physical Exertion / Q000502:physiology; D014176:Protein Biosynthesis / Q000187:drug effects* / Q000502:physiology; D012016:Reference Values; D015398:Signal Transduction / Q000187:drug effects; D055815:Young Adult
chemical_list: D004040:Dietary Carbohydrates; D004044:Dietary Proteins; D006003:Glycogen