Please use this identifier to cite or link to this item: http://hdl.handle.net/1893/12470
Appears in Collections:Faculty of Health Sciences and Sport Journal Articles
Peer Review Status: Refereed
Title: Preexercise aminoacidemia and muscle protein synthesis after resistance exercise
Authors: Burke, Louise M
Hawley, John A
Ross, Megan L
Moore, Daniel R
Phillips, Stuart M
Slater, Gary R
Stellingwerff, Trent
Tipton, Kevin
Garnham, Andrew P
Coffey, Vernon G
Contact Email: k.d.tipton@stir.ac.uk
Keywords: Amino acid delivery
fast and slow proteins
leucine
muscle protein synthesis
Issue Date: Oct-2012
Publisher: American College of Sports Medicine / Lippincott, Williams & Wilkins
Citation: Burke LM, Hawley JA, Ross ML, Moore DR, Phillips SM, Slater GR, Stellingwerff T, Tipton K, Garnham AP & Coffey VG (2012) Preexercise aminoacidemia and muscle protein synthesis after resistance exercise, Medicine and Science in Sports and Exercise, 44 (10), pp. 1968-1977.
Abstract: Purpose: We have previously shown that the aminoacidemia caused by the consumption of a rapidly digested protein after resistance exercise enhances muscle protein synthesis (MPS) more than the amino acid (AA) profile associated with a slowly digested protein. Here, we investigated whether differential feeding patterns of a whey protein mixture commencing before exercise affect postexercise intracellular signaling and MPS. Methods: Twelve resistance-trained males performed leg resistance exercise 45 min after commencing each of three volume-matched nutrition protocols: placebo (PLAC, artificially sweetened water), BOLUS (25 g of whey protein + 5 g of leucine dissolved in artificially sweetened water; 1× 500 mL), or PULSE (15× 33-mL aliquots of BOLUS drink every 15 min). Results: The preexercise rise in plasma AA concentration with PULSE was attenuated compared with BOLUS (P less than 0.05); this effect was reversed after exercise, with two-fold greater leucine concentrations in PULSE compared with BOLUS (P less than 0.05). One-hour postexercise, phosphorylation of p70 S6Kthr389 and rpS6ser235/6 was increased above baseline with BOLUS and PULSE, but not PLAC (P less than 0.05); furthermore, PULSE greater than BOLUS (P less than 0.05). MPS throughout 5 h of recovery was higher with protein ingestion compared with PLAC (0.037 ± 0.007), with no differences between BOLUS or PULSE (0.085 ± 0.013 vs. 0.095 ± 0.010%·h-1, respectively, P = 0.56). Conclusions: Manipulation of aminoacidemia before resistance exercise via different patterns of intake of protein altered plasma AA profiles and postexercise intracellular signaling. However, there was no difference in the enhancement of the muscle protein synthetic response after exercise. Protein sources producing a slow AA release, when consumed before resistance exercise in sufficient amounts, are as effective as rapidly digested proteins in promoting postexercise MPS.
Type: Journal Article
URI: http://hdl.handle.net/1893/12470
DOI Link: http://dx.doi.org/10.1249/MSS.0b013e31825d28fa
Rights: The publisher does not allow this work to be made publicly available in this Repository. Please use the Request a Copy feature at the foot of the Repository record to request a copy directly from the author. You can only request a copy if you wish to use this work for your own research or private study.
Affiliation: Australian Institute of Sport
RMIT University
Australian Institute of Sport
McMaster University
McMaster University
Australian Institute of Sport
Nestle Research Center
Sport
Deakin University
RMIT University

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