1 Attachment(s)
Ingested protein dose response of muscle and albumin protein synthesis after resistan
This is a pretty cool article,
ABSTRACT
Background: The anabolic effect of resistance exercise is enhanced
by the provision of dietary protein.
Objectives: We aimed to determine the ingested protein dose response
of muscle (MPS) and albumin protein synthesis (APS) after
resistance exercise. In addition, we measured the phosphorylation of
candidate signaling proteins thought to regulate acute changes in
MPS.
Design: Six healthy young men reported to the laboratory on 5
separate occasions to perform an intense bout of leg-based resistance
exercise. After exercise, participants consumed, in a randomized
order, drinks containing 0, 5, 10, 20, or 40 g whole egg protein.
Protein synthesis and whole-body leucine oxidation were measured
over 4 h after exercise by a primed constant infusion of [1-13C]leucine.
Results: MPS displayed a dose response to dietary protein ingestion
and was maximally stimulated at 20 g. The phosphorylation of
ribosomal protein S6 kinase (Thr389), ribosomal protein S6 (Ser240/244),
and the e-subunit of eukaryotic initiation factor 2B (Ser539) were
unaffected by protein ingestion. APS increased in a dose-dependent
manner and also reached a plateau at 20 g ingested protein. Leucine
oxidation was significantly increased after 20 and 40 g protein were
ingested.
Conclusions: Ingestion of 20 g intact protein is sufficient to maximally
stimulate MPS and APS after resistance exercise. Phosphorylation
of candidate signaling proteins was not enhanced with any dose
of protein ingested, which suggested that the stimulation of MPS after
resistance exercise may be related to amino acid availability. Finally,
dietary protein consumed after exercise in excess of the rate at which it
can be incorporated into tissue protein stimulates irreversible oxidation.
Am J Clin Nutr 2009;89:161–8.
