title: Pre- versus post-exercise protein intake has similar effects on muscular adaptations.
abstract: The purpose of this study was to test the anabolic window theory by investigating muscle strength, hypertrophy, and body composition changes in response to an equal dose of protein consumed either immediately pre- versus post-resistance training (RT) in trained men. Subjects were 21 resistance-trained men (>1 year RT experience) recruited from a university population. After baseline testing, participants were randomly assigned to 1 of 2 experimental groups: a group that consumed a supplement containing 25 g protein and 1 g carbohydrate immediately prior to exercise (PRE-SUPP) (n= 9) or a group that consumed the same supplement immediately post-exercise (POST-SUPP) (n= 12). The RT protocol consisted of three weekly sessions performed on non-consecutive days for 10 weeks. A total-body routine was employed with three sets of 8-12 repetitions for each exercise. Results showed that pre- and post-workout protein consumption had similar effects on all measures studied (p> 0.05). These findings refute the contention of a narrow post-exercise anabolic window to maximize the muscular response and instead lends support to the theory that the interval for protein intake may be as wide as several hours or perhaps more after a training bout depending on when the pre-workout meal was consumed.
authors.affiliation: Department of Health Sciences, Herbert H. Lehman College, City University of New York , Bronx , NY , United States.
authors.forename: Brad Jon
authors.initials: BJ
authors.lastname: Schoenfeld
authors.affiliation: Department of Nutrition, California State University , Northridge , CA , United States.
authors.forename: Alan
authors.initials: A
authors.lastname: Aragon
authors.affiliation: Graduate School and Research, University of Mary Hardin Baylor , Belton , TX , United States.
authors.forename: Colin
authors.initials: C
authors.lastname: Wilborn
authors.affiliation: Graduate School and Research, University of Mary Hardin Baylor , Belton , TX , United States.
authors.forename: Stacie L
authors.initials: SL
authors.lastname: Urbina
authors.affiliation: Graduate School and Research, University of Mary Hardin Baylor , Belton , TX , United States.
authors.forename: Sara E
authors.initials: SE
authors.lastname: Hayward
authors.affiliation: Weightology , Issaquah , WA , United States.
authors.forename: James
authors.initials: J
authors.lastname: Krieger
keywords: Anabolic window; Nutrient timing; Protein supplementation; Protein timing; Resistance training