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Beneficial Effects of Resistance Exercise on Glycemic Control Are Not Further Improved by Protein Ingestion

Breen, L and Philip, A and Shaw, Christopher and Jeukendrup, A and Baar, K and Tipton, Kevin D (2011) Beneficial Effects of Resistance Exercise on Glycemic Control Are Not Further Improved by Protein Ingestion. PLoS ONE, 6 (6). ISSN 1932-6203 (online)

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Abstract

Purpose To investigate the mechanisms underpinning modifications in glucose homeostasis and insulin sensitivity 24 h after a bout of resistance exercise (RE) with or without protein ingestion. Methods Twenty-four healthy males were assigned to a control (CON; n = 8), exercise (EX; n = 8) or exercise plus protein condition (EX+PRO; n = 8). Muscle biopsy and blood samples were obtained at rest for all groups and immediately post-RE (75% 1RM, 8×10 repetitions of leg-press and extension exercise) for EX and EX+PRO only. At 24 h post-RE (or post-resting biopsy for CON), a further muscle biopsy was obtained. Participants then consumed an oral glucose load (OGTT) containing 2 g of [U-13C] glucose during an infusion of 6, 6-[2H2] glucose. Blood samples were obtained every 10 min for 2 h to determine glucose kinetics. EX+PRO ingested an additional 25 g of intact whey protein with the OGTT. A final biopsy sample was obtained at the end of the OGTT Results Fasted plasma glucose and insulin were similar for all groups and were not different immediately post- and 24 h post-RE. Following RE, muscle glycogen was 26±8 and 19±6% lower in EX and EX+PRO, respectively. During OGTT, plasma glucose AUC was lower for EX and EX+PRO (75.1±2.7 and 75.3±2.8 mmol·L−1:120 min, respectively) compared with CON (90.6±4.1 mmol·L−1:120 min). Plasma insulin response was 13±2 and 21±4% lower for EX and CON, respectively, compared with EX+PRO. Glucose disappearance from the circulation was ~12% greater in EX and EX+PRO compared with CON. Basal 24 h post-RE and insulin-stimulated PAS-AS160/TBC1D4 phosphorylation was greater for EX and EX+PRO. Conclusions Prior RE improves glycemic control and insulin sensitivity through an increase in the rate at which glucose is disposed from the circulation. However, co-ingesting protein during a high-glucose load does not augment this response at 24 h post-exercise in healthy, insulin-sensitive individuals.

Item Type: Article
Uncontrolled Keywords: ResPubID26395, biopsy, exercise, glucose, glucose metabolism, insulin, muscle proteins, oral glucose suppression test, phosphorylation
Subjects: FOR Classification > 1106 Human Movement and Sports Science
Faculty/School/Research Centre/Department > Institute of Sport, Exercise and Active Living (ISEAL)
Depositing User: Ms Phung.T Tran
Date Deposited: 09 Apr 2014 04:39
Last Modified: 13 Aug 2015 02:15
URI: http://vuir.vu.edu.au/id/eprint/23606
DOI: 10.1371/journal.pone.0020613
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Citations in Scopus: 6 - View on Scopus

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