Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2013 Dec 3;10(1):53.
doi: 10.1186/1550-2783-10-53.

The Effect of Protein Timing on Muscle Strength and Hypertrophy: A Meta-Analysis

Free PMC article

The Effect of Protein Timing on Muscle Strength and Hypertrophy: A Meta-Analysis

Brad Jon Schoenfeld et al. J Int Soc Sports Nutr. .
Free PMC article


Protein timing is a popular dietary strategy designed to optimize the adaptive response to exercise. The strategy involves consuming protein in and around a training session in an effort to facilitate muscular repair and remodeling, and thereby enhance post-exercise strength- and hypertrophy-related adaptations. Despite the apparent biological plausibility of the strategy, however, the effectiveness of protein timing in chronic training studies has been decidedly mixed. The purpose of this paper therefore was to conduct a multi-level meta-regression of randomized controlled trials to determine whether protein timing is a viable strategy for enhancing post-exercise muscular adaptations. The strength analysis comprised 478 subjects and 96 ESs, nested within 41 treatment or control groups and 20 studies. The hypertrophy analysis comprised 525 subjects and 132 ESs, nested with 47 treatment or control groups and 23 studies. A simple pooled analysis of protein timing without controlling for covariates showed a small to moderate effect on muscle hypertrophy with no significant effect found on muscle strength. In the full meta-regression model controlling for all covariates, however, no significant differences were found between treatment and control for strength or hypertrophy. The reduced model was not significantly different from the full model for either strength or hypertrophy. With respect to hypertrophy, total protein intake was the strongest predictor of ES magnitude. These results refute the commonly held belief that the timing of protein intake in and around a training session is critical to muscular adaptations and indicate that consuming adequate protein in combination with resistance exercise is the key factor for maximizing muscle protein accretion.


Figure 1
Figure 1
Impact of protein timing on strength by study.
Figure 2
Figure 2
Impact of protein timing on hypertrophy by study.
Figure 3
Figure 3
Impact of protein timing on hypertrophy by study, adjusted for total protein intake.

Comment in

Similar articles

See all similar articles

Cited by 47 articles

See all "Cited by" articles


    1. Phillips SM, Van Loon LJ. et al. Dietary protein for athletes: from requirements to optimum adaptation. J Sports Sci. 2011;10((Suppl 1)):S29–38. - PubMed
    1. Kerksick C, Harvey T, Stout J, Campbell B, Wilborn C, Kreider R. et al. International society of sports nutrition position stand: nutrient timing. J Int Soc Sports Nutr. 2008 Oct 3;10:17. - PMC - PubMed
    1. Lemon PW, Berardi JM, Noreen EE. The role of protein and amino acid supplements in the athlete's diet: does type or timing of ingestion matter? Curr Sports Med Rep. 2002 Aug;10(4):214–221. - PubMed
    1. Ivy J, Portman R. Nutrient timing: The future of sports nutrition. North Bergen, NJ: Basic Health Publications; 2004.
    1. Candow DG, Chilibeck PD. Timing of creatine or protein supplementation and resistance training in the elderly. Appl Physiol Nutr Metab. 2008 Feb;10(1):184–190. - PubMed

LinkOut - more resources