Deakin University
Browse

File(s) under permanent embargo

Preexercise aminoacidemia and muscle protein synthesis after resistance exercise

Version 2 2024-06-04, 12:06
Version 1 2015-08-17, 14:40
journal contribution
posted on 2024-06-04, 12:06 authored by LM Burke, JA Hawley, ML Ross, DR Moore, SM Phillips, GR Slater, T Stellingwerff, KD Tipton, Andrew GarnhamAndrew Garnham, VG Coffey
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 < 0.05); this effect was reversed after exercise, with two-fold greater leucine concentrations in PULSE compared with BOLUS (P < 0.05). One-hour postexercise, phosphorylation of p70 S6K(thr389) and rpS6(ser235/6) was increased above baseline with BOLUS and PULSE, but not PLAC (P < 0.05); furthermore, PULSE > BOLUS (P < 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.

History

Journal

Medicine & science in sports & exercise

Volume

44

Pagination

1968-1977

Location

Philadelphia, Pa.

ISSN

0195-9131

eISSN

1530-0315

Language

eng

Publication classification

C Journal article, C1.1 Refereed article in a scholarly journal

Copyright notice

2012, American College of Sports Medicine

Issue

10

Publisher

Lippincott Williams & Wilkins