Effect of Protein Intake on Strength, Body Composition and Endocrine Changes in Strength/Power Athletes

Comparison of protein intakes on strength, body composition and hormonal changes were examined in 23 experienced collegiate strength/power athletes participating in a 12-week resistance training program. Subjects were stratified into three groups depending upon their daily consumption of protein; be...

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Main Authors:	Hoffman, Jay R, Ratamess, Nicholas A, Kang, Jie, Falvo, Michael J, Faigenbaum, Avery D
Format:	Online
Language:	English
Published:	BioMed Central 2006
Online Access:	https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2129168/

id	pubmed-2129168
recordtype	oai_dc
spelling	pubmed-21291682007-12-12 Effect of Protein Intake on Strength, Body Composition and Endocrine Changes in Strength/Power Athletes Hoffman, Jay R Ratamess, Nicholas A Kang, Jie Falvo, Michael J Faigenbaum, Avery D Research Article Comparison of protein intakes on strength, body composition and hormonal changes were examined in 23 experienced collegiate strength/power athletes participating in a 12-week resistance training program. Subjects were stratified into three groups depending upon their daily consumption of protein; below recommended levels (BL; 1.0 – 1.4 g·kg-1·day-1; n = 8), recommended levels (RL; 1.6 – 1.8 g·kg-1·day-1; n = 7) and above recommended levels (AL; > 2.0 g·kg-1·day-1; n = 8). Subjects were assessed for strength [one-repetition maximum (1-RM) bench press and squat] and body composition. Resting blood samples were analyzed for total testosterone, cortisol, growth hormone, and insulin-like growth factor. No differences were seen in energy intake (3,171 ± 577 kcal) between the groups, and the energy intake for all groups were also below the recommended levels for strength/power athletes. No significant changes were seen in body mass, lean body mass or fat mass in any group. Significant improvements in 1-RM bench press and 1-RM squat were seen in all three groups, however no differences between the groups were observed. Subjects in AL experienced a 22% and 42% greater change in Δ 1-RM squat and Δ 1-RM bench press than subjects in RL, however these differences were not significant. No significant changes were seen in any of the resting hormonal concentrations. The results of this study do not provide support for protein intakes greater than recommended levels in collegiate strength/power athletes for body composition improvements, or alterations in resting hormonal concentrations. BioMed Central 2006-12-13 /pmc/articles/PMC2129168/ /pubmed/18500968 http://dx.doi.org/10.1186/1550-2783-3-2-12 Text en Copyright © 2006 A National Library of Congress Indexed Journal
repository_type	Open Access Journal
institution_category	Foreign Institution
institution	US National Center for Biotechnology Information
building	NCBI PubMed
collection	Online Access
language	English
format	Online
author	Hoffman, Jay R Ratamess, Nicholas A Kang, Jie Falvo, Michael J Faigenbaum, Avery D
spellingShingle	Hoffman, Jay R Ratamess, Nicholas A Kang, Jie Falvo, Michael J Faigenbaum, Avery D Effect of Protein Intake on Strength, Body Composition and Endocrine Changes in Strength/Power Athletes
author_facet	Hoffman, Jay R Ratamess, Nicholas A Kang, Jie Falvo, Michael J Faigenbaum, Avery D
author_sort	Hoffman, Jay R
title	Effect of Protein Intake on Strength, Body Composition and Endocrine Changes in Strength/Power Athletes
title_short	Effect of Protein Intake on Strength, Body Composition and Endocrine Changes in Strength/Power Athletes
title_full	Effect of Protein Intake on Strength, Body Composition and Endocrine Changes in Strength/Power Athletes
title_fullStr	Effect of Protein Intake on Strength, Body Composition and Endocrine Changes in Strength/Power Athletes
title_full_unstemmed	Effect of Protein Intake on Strength, Body Composition and Endocrine Changes in Strength/Power Athletes
title_sort	effect of protein intake on strength, body composition and endocrine changes in strength/power athletes
description	Comparison of protein intakes on strength, body composition and hormonal changes were examined in 23 experienced collegiate strength/power athletes participating in a 12-week resistance training program. Subjects were stratified into three groups depending upon their daily consumption of protein; below recommended levels (BL; 1.0 – 1.4 g·kg-1·day-1; n = 8), recommended levels (RL; 1.6 – 1.8 g·kg-1·day-1; n = 7) and above recommended levels (AL; > 2.0 g·kg-1·day-1; n = 8). Subjects were assessed for strength [one-repetition maximum (1-RM) bench press and squat] and body composition. Resting blood samples were analyzed for total testosterone, cortisol, growth hormone, and insulin-like growth factor. No differences were seen in energy intake (3,171 ± 577 kcal) between the groups, and the energy intake for all groups were also below the recommended levels for strength/power athletes. No significant changes were seen in body mass, lean body mass or fat mass in any group. Significant improvements in 1-RM bench press and 1-RM squat were seen in all three groups, however no differences between the groups were observed. Subjects in AL experienced a 22% and 42% greater change in Δ 1-RM squat and Δ 1-RM bench press than subjects in RL, however these differences were not significant. No significant changes were seen in any of the resting hormonal concentrations. The results of this study do not provide support for protein intakes greater than recommended levels in collegiate strength/power athletes for body composition improvements, or alterations in resting hormonal concentrations.
publisher	BioMed Central
publishDate	2006
url	https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2129168/
_version_	1611417527163813888

Effect of Protein Intake on Strength, Body Composition and Endocrine Changes in Strength/Power Athletes

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