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(vagrant @ Oct. 31 2006,06:57)</div><div id="QUOTEHEAD">QUOTE</div><div id="QUOTE"><div>
(Aaron_F @ Oct. 30 2006,02:47)</div><div id="QUOTEHEAD">QUOTE</div><div id="QUOTE"><div>
(vagrant @ Oct. 30 2006,14:48)</div><div id="QUOTEHEAD">QUOTE</div><div id="QUOTE">More insulin after a workout = more muscle.</div>
there is really absolutely no evidence that more is better.</div>
OK.
However, since I started doing this - I gained 30lbs in only 2 months. Lowered my BF% at the same time. This is with a normal test level for a 37 year old man.</div>
So?
<div></div><div id="QUOTEHEAD">QUOTE</div><div id="QUOTE">And yes, Arron, insulin is very anabolic. You are the scientist, please find the definition of anabolic and share it with us. I'm pretty sure that it means it promotes growth.</div>
On a base level, anabolism is creating larger molecules from smaller, with catabolism meaning the opposite. On a gross, whole body scale, anabolism means growing and catabolism means shrinking.
Insulin pretty much operates in a permissive role in protein synthesis. The level which this effect happens is around fasted levels.
see
Invited Review: Role of insulin in translational control of protein synthesis in skeletal muscle by amino acids or exercise.
* Kimball SR,
* Farrell PA,
* Jefferson LS.
Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033, USA
Protein synthesis in skeletal muscle is modulated in response to a variety of stimuli. Two stimuli receiving a great deal of recent attention are increased amino acid availability and exercise. Both of these effectors stimulate protein synthesis in part through activation of translation initiation. However, the full response of translation initiation and protein synthesis to either effector is not observed in the absence of a minimal concentration of insulin. The combination of insulin and either increased amino acid availability or endurance exercise stimulates translation initiation and protein synthesis in part through activation of the ribosomal protein S6 protein kinase S6K1 as well as through enhanced association of eukaryotic initiation factor eIF4G with eIF4E, an event that promotes binding of mRNA to the ribosome. 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. This review summarizes the results of a number of recent studies that have helped to establish our present understanding of the interactions of insulin, amino acids, and exercise in the regulation of protein synthesis in skeletal muscle.
Some trials show an effect of insulin on protein synthesis (anabolism), others show no effect. Animal trials have looked at the dose response effect of insulin on protein synthesis, and showed what was mentioned above. Human work has not examined this.
The main effect of insulin on protein balance is via reducing intracelluar breakdown (reducing catabolism, not anabolic per se - however on a gross level is classified as anabolism).
see
Mechanism of insulin's anabolic effect on muscle: measurements of muscle protein synthesis and breakdown using aminoacyl-tRNA and other surrogate measures.
* Chow LS,
* Albright RC,
* Bigelow ML,
* Toffolo G,
* Cobelli C,
* Nair KS.
Division of Endocrinology, Mayo Clinic College of Medicine, 200 First St. SW, Rochester, MN 55905, USA.
Despite being an anabolic hormone in skeletal muscle, insulin's anticatabolic mechanism in humans remains controversial, with contradictory reports showing either stimulation of protein synthesis (PS) or inhibition of protein breakdown (PB) by insulin. Earlier measurements of muscle PS and PB in humans have relied on different surrogate measures of aminoacyl-tRNA and intracellular pools. We report that insulin's effect on muscle protein turnover using aminoacyl-tRNA as the precursor of PS and PB is calculated by mass balance of tracee amino acid (AA). We compared the results calculated from various surrogate measures. To determine the physiological role of insulin on muscle protein metabolism, we infused tracers of leucine and phenylalanine into 18 healthy subjects, and after 3 h, 10 subjects received a 4-h femoral arterial infusion of insulin (0.125 mUxkg(-1)xmin(-1)), while eight subjects continued with saline. Tracer-to-tracee ratios of leucine, phenylalanine, and ketoisocaproate were measured in the arterial and venous plasma, muscle tissue fluid, and AA-tRNA to calculate muscle PB and PS. Insulin infusion, unlike saline, significantly reduced the efflux of leucine and phenylalanine from muscle bed, based on various surrogate measures which agreed with those based on leucyl-tRNA (-28%), indicating a reduction in muscle PB (P < 0.02) without any significant effect on muscle PS.
In conclusion, using AA-tRNA as the precursor pool, it is demonstrated that, in healthy humans in the postabsorptive state, insulin does not stimulate muscle protein synthesis and confirmed that insulin achieves muscle protein anabolism by inhibition of muscle protein breakdown.
There is no evidence in humans examining what level of insulin is required to achieve the maximum level of breakdown.
so as I said the first time
<div></div><div id="QUOTEHEAD">QUOTE</div><div id="QUOTE">there is really absolutely no evidence that more is better.</div>
