Format

Send to

Choose Destination
Med Sci Sports Exerc. 2011 Jul;43(7):1154-61. doi: 10.1249/MSS.0b013e31820751cb.

Carbohydrate does not augment exercise-induced protein accretion versus protein alone.

Author information

1
Exercise Metabolism Research Group, Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada.

Abstract

PURPOSE:

We tested the thesis that CHO and protein coingestion would augment muscle protein synthesis (MPS) and inhibit muscle protein breakdown (MPB) at rest and after resistance exercise.

METHODS:

Nine men (age=23.0±1.9 yr, body mass index=24.2±2.1 kg·m) performed two unilateral knee extension trials (four sets×8-12 repetitions to failure) followed by consumption of 25 g of whey protein (PRO) or 25 g of whey protein plus 50 g of maltodextrin (PRO+CARB). Muscle biopsies and stable isotope methodology were used to measure MPS and MPB.

RESULTS:

The areas under the glucose and insulin curves were 17.5-fold (P<0.05) and 5-fold (P<0.05) greater, respectively, for PRO+CARB than for PRO. Exercise increased MPS and MPB (both P<0.05), but there were no differences between PRO and PRO+CARB in the rested or exercised legs. Phosphorylation of Akt was greater in the PRO+CARB than in the PRO trial (P<0.05); phosphorylations of Akt (P=0.05) and acetyl coA carboxylase-β (P<0.05) were greater after exercise than at rest. The concurrent ingestion of 50 g of CHO with 25 g of protein did not stimulate mixed MPS or inhibit MPB more than 25 g of protein alone either at rest or after resistance exercise.

CONCLUSIONS:

Our data suggest that insulin is not additive or synergistic to rates of MPS or MPB when CHO is coingested with a dose of protein that maximally stimulates rates of MPS.

PMID:
21131864
DOI:
10.1249/MSS.0b013e31820751cb
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Wolters Kluwer
Loading ...
Support Center