That WAS my point. Glycogen storage within normal parameters ISN'T that important.
Wrong. Amino acids are the main nutrient signals for protein synthesis, NOT insulin. And speed when it comes to amino acids is important. Guess what also triggers an insulin response and actually eliminates cortisol....amino acids. IF you are worries so much about preventing catabolism then increasing rates of protein synthesis should be your number one priority. Insulin is mainly anti-catabolic in small amounts. Amino acids exert anabolic activity.
Amino Acids Stimulate Translation Initiation and Protein Synthesis through an Akt-Independent Pathway in Human Skeletal Muscle
Zhenqi Liu, Linda A. Jahn, Liping Wei, Wen Long and Eugene J. Barrett
Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Virginia Health Sciences Center, Charlottesville, Virginia 22908
Address all correspondence and requests for reprints to: Zhenqi Liu, M.D., Division of Endocrinology and Metabolism, Department of Internal Medicine, P.O. Box 801410, University of Virginia Health Sciences Center, Charlottesville, Virginia 22908. E-mail:
[email protected].
Abstract
Studies in vitro as well as in vivo in rodents have suggested that amino acids (AA) not only serve as substrates for protein synthesis, but also as nutrient signals to enhance mRNA translation and protein synthesis in skeletal muscle. However, the physiological relevance of these findings to normal humans is uncertain. To examine whether AA regulate the protein synthetic apparatus in human skeletal muscle, we infused an AA mixture (10% Travesol) systemically into 10 young healthy male volunteers for 6 h. Forearm muscle protein synthesis and degradation (phenylalanine tracer method) and the phosphorylation of protein kinase B (or Akt), eukaryotic initiation factor 4E-binding protein 1, and ribosomal protein S6 kinase (p70S6K) in vastus lateralis muscle were measured before and after AA infusion. We also examined whether AA affect urinary nitrogen excretion and whole body protein turnover.
Postabsorptively all subjects had negative forearm phenylalanine balances. AA infusion significantly improved the net phenylalanine balance at both 3 h (P < 0.002) and 6 h (P < 0.02). This improvement in phenylalanine balance was solely from increased protein synthesis (P = 0.02 at 3 h and P < 0.003 at 6 h), as protein degradation was not changed. AA also significantly decreased whole body phenylalanine flux (P < 0.004). AA did not activate Akt phosphorylation at Ser473, but significantly increased the phosphorylation of both eukaryotic initiation factor 4E-binding protein 1 (P < 0.04) and p70S6K (P < 0.001).
We conclude that AA act directly as nutrient signals to stimulate protein synthesis through Akt-independent activation of the protein synthetic apparatus in human skeletal muscle.
Exercise Effects on Muscle Insulin Signaling and Action
Invited Review: Role of insulin in translational control of protein synthesis in skeletal muscle by amino acids or exercise
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In contrast, insulin in combination with resistance exercise stimulates translation initiation and protein synthesis through enhanced activity of a guanine nucleotide exchange protein referred to as eIF2B. In both cases, the amount of insulin required for the effects is low, and a concentration of the hormone that approximates that observed in fasting animals is sufficient for maximal stimulation.
In your exuberance to flex you intellectual muscle and to prove me wrong, you have only reinforced my point that refilling glycogen store as fast as possible isn't important. I've been saying it for years.
