insulin article

[Dtlv74]

I think some people read a bit about insulin and confuse it with IGF1 (Insulin-like growth factor 1) which is anabolic in a way desirable for someone looking to stay lean but build up muscle. The confusion lies in that although IGF1 uses insulin receptors it is actually derived from hGH - the release of which is often inhibited by insulin.

If you are interested in getting big and muscular but staying lean, you'll do best to look for methods of diet and training which naturally increase hGH and testosterone rather than insulin.

[NU_nutrition_TS]

Well said, Dtlv!

[NU_nutrition_TS]

One more nail in the coffin of insulin spiking to promote protein synthesis:

Quote

J Appl Physiol Articles in PresS. Published on June 7, 2002 as DOI 10.1152/japplphysiol.00221.2002

Role of Insulin in Translational Control of Protein Synthesis in Skeletal Muscle by Amino Acids or Exercise

Scot R. Kimball1, Peter A. Farrell2, and Leonard S. Jefferson1

1Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, PA 17033; 2Noll Physiology Research Center, The Pennsylvania State
University, University Park, PA 16802

Abstract
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 current understanding of the interactions of insulin, amino acids, and exercise in the regulation of protein synthesis in skeletal muscle.

Hence, as I keep saying, why insulin sensitivity is increased after exercise so that increased insulin is not required!

[yazsas]

I agree

[fatboyginger]

Can you not buy a pill that blocks insulin? Scofield bought one in prison break in order to pretend that he had diabetes.

[NU_nutrition_TS]

I think that may have been 'artistic licence' on the part of the scriptwriters...blocking insulin completely would be very dangerous, so if there were a drug capable of doing that it would be a very 'controlled' substance!

[Aren_Tyr]

Brilliant thread.

I've been experimenting with various protocols myself recently, as theory is all good and well, but the "proof is in the pudding" as the saying goes, and have come to agree completely with the conclusions in this thread.

Having substantial amounts of post-workout carbs is simply not necessary. I typically workout in the evening, and quite simply it is better to consume the majority of your carbs earlier on in the day when the glycogen will be used and your natural metabolism is elevated.

I specifically tried a very low-carb evening a few days ago post workout. Had my usual post-workout shake with a small amount of WMS (about 20g) and whey etc., then my meal about 40 minutes later, which was most definitely a "Paleo" meal (salmon, beansprouts, lettuce, peppers; no grains or major carb source), then a bit later my pre-bed shake of milk protein concentrate, Omega 3-6-9 oil etc.

Woke up in the morning feeling fine, no muscular soreness any different to a standard carb-rich evening, fully recovered, maybe just a slightly "empty" or hungry feeling. However, by the time I'd had my proper fairly carb-rich breakfast at 10:30 AM, felt absolutely fine and "replenished". Workout that evening was as good as always.

So in conclusion, I think the body is pretty damn efficient at replenishing glycogen levels, and it isn't critical or indeed necessarily beneficial to do so immediately, particularly if the cost of doing so is to spike your insulin levels substantially.

I've been trying to keep my carb levels fairly low in the evening post workout. The result of this is that I am losing body fat and still adding muscle and getting stronger. I think the only reason for rapid glycogen replenishment is if you need to do so to ensure you are ready to do some more intense exercise fairly soon.

But for anyone not currently engaged during type of continuous endurance event, the average person, or indeed the ultra fit Paleo man (which is what we should all aim for), then staying away from high-GI carbs at any time is a good thing.

Overall I think the carbohydrate requirement is far less than most people consume, even for heavy exercisers, and they would be better making up any calorie shortfall from fat and protein.

The carbohydrate rich diet of the latter part of the 20th century onwards is what is turning us into a world of fatties.

A certain amount of carbohydrate certainly does help exercise performance, but the level is much lower than most people consume who follow typical "sports nutrition" advice, I believe.

Quote

As yazsas has said, spiking insulin immediately after training by taking high GI carbs just to replenish glycogen blunts all the REAL anabolic hormones while doing it to facilitate protein synthesis is a bit like deliberately putting a hole in your boat then bailing it out with a teaspoon!

Great extract Nu

Quote

Can you not buy a pill that blocks insulin?

That would be extremely dangerous and extremely stupid. Insulin is a critical hormone, and blocking it would mean that you would have permanently elevated blood sugar levels. This would effectively put you into a diabetic state, with all the various health problems. You'd be putting nearly all your major organs at risk of systematic and serious damage if you stayed in that state for any length of time, and you'd also start to feel quite ill.

[allthegoodnamesaregone]

Insulin is not anabolic but anti catabolic post work out, still no reason to use high GI carbs to do it though.

I'm thinking the whole pre workout / post workout nutrition may well be the wrong way round. A fast acting high GI carb and fast acting protein or BCAA combo make more sense pre workout when blood flow is about to be increased to the muscles and insulins anti catabolic properties will be required shortly.

Then post workout the opposite is true a slow protein source and carb source will work better so more of it gets up taken. Certainly as we are discussing this in the advanced section it is fair to say studies show little difference in carb uptake between high and low GI carbs post workout.

Still this is neither new or my own theory.

[NU_nutrition_TS]

Insulin-Like Growth Factor (IGF) I is superior to insulin in that it exhibits both anabolic and anticatabolic functions.

In skeletal muscle, circulating plasma IGF-I concentrations stimulate intracellular amino acid and glucose transport as well as protein synthesis while suppressing protein degradation (Musey and others 1993).

Growth hormone stimulates the secretion of IGF-1. The liver is a major target organ of GH for this process, and is the principal site of IGF-1 production.

The most important point in regards to growth hormone (GH) and diet is that "Growth hormone levels increase significantly when insulin levels are low" (Jamieson, p. 85). "More precisely, the cause of growth hormone inhibition is not high insulin levels but rather high blood sugar (which, because insulin is secreted to bring down blood sugar level, overlaps in time with high insulin levels)" (Faigin, p.201).

So high GI carb ingestion immediately before or after exercise is not such a good idea for muscle tissue growth. If your goal is to lose excess fat while gaining [or not losing] lean mass then high GI carbs and insulin spikes immediately before exercise are a no-no from the pint of view of blunted lipolysis and increased lipogenesis.