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Effects of whey isolate, creatine, and resistance training on muscle hypertrophy.
Med Sci Sports Exerc. 2007 Feb; 39(2):298-307.MS

Abstract

PURPOSE

Studies that have attributed gains in lean body mass to dietary supplementation during resistance exercise (RE) training have not reported these changes alongside adaptations at the cellular and subcellular levels. Therefore, the purpose of this study was to examine the effects of two popular supplements--whey protein (WP) and creatine monohydrate (CrM) (both separately and in combination)--on body composition, muscle strength, fiber-specific hypertrophy (i.e., type I, IIa, IIx), and contractile protein accrual during RE training.

METHODS

In a double-blind randomized protocol, resistance-trained males were matched for strength and placed into one of four groups: creatine/carbohydrate (CrCHO), creatine/whey protein (CrWP), WP only, or carbohydrate only (CHO) (1.5 g x kg(-1) body weight per day). All assessments were completed the week before and after an 11-wk structured, supervised RE program. Assessments included strength (1RM, three exercises), body composition (DEXA), and vastus lateralis muscle biopsies for determination of muscle fiber type (I, IIa, IIx), cross-sectional area (CSA), contractile protein, and creatine (Cr) content.

RESULTS

Supplementation with CrCHO, WP, and CrWP resulted in significantly greater (P < 0.05) 1RM strength improvements (three of three assessments) and muscle hypertrophy compared with CHO. Up to 76% of the strength improvements in the squat could be attributed to hypertrophy of muscle involved in this exercise. However, the hypertrophy responses within these groups varied at the three levels assessed (i.e., changes in lean mass, fiber-specific hypertrophy, and contractile protein content).

CONCLUSIONS

Although WP and/or CrM seem to promote greater strength gains and muscle morphology during RE training, the hypertrophy responses within the groups varied. These differences in skeletal muscle morphology may have important implications for various populations and, therefore, warrant further investigation.

Authors+Show Affiliations

Exercise Metabolism Unit, Center for Ageing, Rehabilitation, Exercise and Sport and the School of Biomedical Sciences, Victoria University, Victoria, Australia.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Clinical Trial
Journal Article
Randomized Controlled Trial

Language

eng

PubMed ID

17277594

Citation

Cribb, Paul J., et al. "Effects of Whey Isolate, Creatine, and Resistance Training On Muscle Hypertrophy." Medicine and Science in Sports and Exercise, vol. 39, no. 2, 2007, pp. 298-307.
Cribb PJ, Williams AD, Stathis CG, et al. Effects of whey isolate, creatine, and resistance training on muscle hypertrophy. Med Sci Sports Exerc. 2007;39(2):298-307.
Cribb, P. J., Williams, A. D., Stathis, C. G., Carey, M. F., & Hayes, A. (2007). Effects of whey isolate, creatine, and resistance training on muscle hypertrophy. Medicine and Science in Sports and Exercise, 39(2), 298-307.
Cribb PJ, et al. Effects of Whey Isolate, Creatine, and Resistance Training On Muscle Hypertrophy. Med Sci Sports Exerc. 2007;39(2):298-307. PubMed PMID: 17277594.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Effects of whey isolate, creatine, and resistance training on muscle hypertrophy. AU - Cribb,Paul J, AU - Williams,Andrew D, AU - Stathis,Chris G, AU - Carey,Michael F, AU - Hayes,Alan, PY - 2007/2/6/pubmed PY - 2007/4/11/medline PY - 2007/2/6/entrez SP - 298 EP - 307 JF - Medicine and science in sports and exercise JO - Med Sci Sports Exerc VL - 39 IS - 2 N2 - PURPOSE: Studies that have attributed gains in lean body mass to dietary supplementation during resistance exercise (RE) training have not reported these changes alongside adaptations at the cellular and subcellular levels. Therefore, the purpose of this study was to examine the effects of two popular supplements--whey protein (WP) and creatine monohydrate (CrM) (both separately and in combination)--on body composition, muscle strength, fiber-specific hypertrophy (i.e., type I, IIa, IIx), and contractile protein accrual during RE training. METHODS: In a double-blind randomized protocol, resistance-trained males were matched for strength and placed into one of four groups: creatine/carbohydrate (CrCHO), creatine/whey protein (CrWP), WP only, or carbohydrate only (CHO) (1.5 g x kg(-1) body weight per day). All assessments were completed the week before and after an 11-wk structured, supervised RE program. Assessments included strength (1RM, three exercises), body composition (DEXA), and vastus lateralis muscle biopsies for determination of muscle fiber type (I, IIa, IIx), cross-sectional area (CSA), contractile protein, and creatine (Cr) content. RESULTS: Supplementation with CrCHO, WP, and CrWP resulted in significantly greater (P < 0.05) 1RM strength improvements (three of three assessments) and muscle hypertrophy compared with CHO. Up to 76% of the strength improvements in the squat could be attributed to hypertrophy of muscle involved in this exercise. However, the hypertrophy responses within these groups varied at the three levels assessed (i.e., changes in lean mass, fiber-specific hypertrophy, and contractile protein content). CONCLUSIONS: Although WP and/or CrM seem to promote greater strength gains and muscle morphology during RE training, the hypertrophy responses within the groups varied. These differences in skeletal muscle morphology may have important implications for various populations and, therefore, warrant further investigation. SN - 0195-9131 UR - https://www.unboundmedicine.com/medline/citation/17277594/Effects_of_whey_isolate_creatine_and_resistance_training_on_muscle_hypertrophy_ L2 - https://doi.org/10.1249/01.mss.0000247002.32589.ef DB - PRIME DP - Unbound Medicine ER -