New PWO info, with references

[Alpha-Male]

so you're saying that's not the abstract you got your original info from? hmm, well then where is the abstract stating that insulin spikes post exercise do not effect protein synthesis?

[Giantz11]

Can J Appl Physiol. 1995 Dec;20(4):480-6
The time course for elevated muscle protein synthesis following heavy resistance exercise.

MacDougall JD, Gibala MJ, Tarnopolsky MA, MacDonald JR, Interisano SA, Yarasheski KE.

Department of Kinesiology, McMaster University, Hamilton, Ontario.

It has been shown that muscle protein synthetic rate (MPS) is elevated in humans by 50% at 4 hrs following a bout of heavy resistance training, and by 109% at 24 hrs following training. This study further examined the time course for elevated muscle protein synthesis by examining its rate at 36 hrs following a training session. Six healthy young men performed 12 sets of 6- to 12-RM elbow flexion exercises with one arm while the opposite arm served as a control. MPS was calculated from the in vivo rate of incorporation of L-[1,2-13C2] leucine into biceps brachii of both arms using the primed constant infusion technique over 11 hrs. At an average time of 36 hrs postexercise, MPS in the exercised arm had returned to within 14% of the control arm value, the difference being nonsignificant. It is concluded that following a bout of heavy resistance training, MPS increases rapidly, is more than double at 24 hrs, and thereafter declines rapidly so that at 36 hrs it has almost returned to baseline.

[Giantz11]

Physiological hyperinsulinemia stimulates p70(S6k) phosphorylation in human skeletal muscle.

Hillier T, Long W, Jahn L, Wei L, Barrett EJ.

Department of Internal Medicine, Division of Endocrinology, University of Virginia School of Medicine, Charlottesville, Virginia 22908, USA.

Using tracer methods, insulin stimulates muscle protein synthesis in vitro, an effect not seen in vivo with physiological insulin concentrations in adult animals or humans. To examine the action of physiological hyperinsulinemia on protein synthesis using a tracer-independent method in vivo and identify possible explanations for this discrepancy, we measured the phosphorylation of ribosomal protein S6 kinase (P70(S6k)) and eIF4E-binding protein (eIF4E-BP1), two key proteins that regulate messenger ribonucleic acid translation and protein synthesis. Postabsorptive healthy adults received either a 2-h insulin infusion (1 mU/min.kg; euglycemic insulin clamp; n = 6) or a 2-h s****e infusion (n = 5). Vastus lateralis muscle was biopsied at baseline and at the end of the infusion period. Phosphorylation of P70(S6k) and eIF4E-BP1 was quantified on Western blots after SDS-PAGE. Physiological increments in plasma insulin (42 +/- 13 to 366 +/- 36 pmol/L; P: = 0.0002) significantly increased p70(S6k) (P: < 0.01), but did not affect eIF4E-BP1 phosphorylation in muscle. Plasma insulin declined slightly during s****e infusion (P: = 0.04), and there was no change in the phosphorylation of either p70(S6k) or eIF4E-BP1. These findings indicate an important role of physiological hyperinsulinemia in the regulation of p70(S6k) in human muscle. This finding is consistent with a potential role for insulin in regulating the synthesis of that subset of proteins involved in ribosomal function. The failure to enhance the phosphorylation of eIF4E-BP1 may in part explain the lack of a stimulatory effect of physiological hyperinsulinemia on bulk protein synthesis in skeletal muscle in vivo.

[Alpha-Male]

swing and a miss!

the first one doesnt mention anything about an insulin spike post exercise not having an effect on protein synthesis...the second one doesnt measure anything following EXERCISE, i.e., weight training...too many "may"s and "might"s...

[Giantz11]

I don't believe that the second one has to say anything about exercise it relates insulin to protein syntheis, period. After exercise one is looking to maximize protein synthesis.

[Alpha-Male]

immediately after exercise, the body is EXTREMELY sensitive to insulin , so i think it would most certainly need to...

[Giantz11]

Insulin sensitivity of protein and glucose metabolism in human forearm skeletal muscle.

Louard RJ, Fryburg DA, Gelfand RA, Barrett EJ.

Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06510.

Physiologic increases of insulin promote net amino acid uptake and protein anabolism in forearm skeletal muscle by restraining protein degradation. The sensitivity of this process to insulin is not known. Using the forearm perfusion method, we infused insulin locally in the brachial artery at rates of 0.00 (s****e control), 0.01, 0.02, 0.035, or 0.05 mU/min per kg for 150 min to increase local forearm plasma insulin concentration by 0, approximately 20, approximately 35, approximately 60, and approximately 120 microU/ml (n = 35). L-[ring-2,6-3H]phenylalanine and L-[1-14C]leucine were infused systemically, and the net forearm balance, rate of appearance (Ra) and rate of disposal (R(d)) of phenylalanine and leucine, and forearm glucose balance were measured basally and in response to insulin infusion. Compared to s****e, increasing rates of insulin infusion progressively increased net forearm glucose uptake from 0.9 mumol/min per 100 ml (s****e) to 1.0, 1.8, 2.4, and 4.7 mumol/min per 100 ml forearm, respectively. Net forearm balance for phenylalanine and leucine was significantly less negative than basal (P < 0.01 for each) in response to the lowest dose insulin infusion, 0.01 mU/min per kg, and all higher rates of insulin infusion. Phenylalanine and leucine R(a) declined by approximately 38 and 40% with the lowest dose insulin infusion. Higher doses of insulin produced no greater effect (decline in R(a) varied between 26 and 42% for phenylalanine and 30-50% for leucine). In contrast, R(d) for phenylalanine and leucine did not change with insulin. We conclude that even modest increases of plasma insulin can markedly suppress proteolysis, measured by phenylalanine R(a), in human forearm skeletal muscle. Further increments of insulin within the physiologic range augment glucose uptake but have little additional effect on phenylalanine R(a) or balance. These results suggest that proteolysis in human skeletal muscle is more sensitive than glucose uptake to physiologic increments in insulin.

[Giantz11]

Higher doses of insulin produced no greater effect (decline in R(a) varied between 26 and 42% for phenylalanine and 30-50% for leucine).

[Alpha-Male]

so you're saying that those levels of infused insulin are comparable to the levels reached immediately post-exercise or with the addition of a high glycemic carb-protein shake? my guess would be no...

[Giantz11]

If anything they are even higher than levels that can be reached PWO through CHO ingestion.

[Giantz11]

Actually, I retract what I said above. These ranges are physiological ranges.

Further increments of insulin within the physiologic range augment glucose uptake but have little additional effect on phenylalanine R(a) or balance. These results suggest that proteolysis in human skeletal muscle is more sensitive than glucose uptake to physiologic increments in insulin.

[Alpha-Male]

eh, i'd rather see a study done that measured insulin levels following a workout with ingestion of above mentioned supplement...

[*Narkissos*]

all sides of this argument put forth interesting hypotheses