How does insulin actually build muscle?

[littleguy289]

Ok, I understand what insulin does, but that's just it- insulin is anabolic, but ONLY to insulin receptors. Right? And insulin receptors are gates that are only receptive to glucose. So, I can understand the value of wanting to pack as much glucose into muscle cells as possible, but that's more for maximizing ATP production for muscle energy, strength, stamina, etc. Ie- best BEFORE workout to fuel said workout. But post workout, isn't all that glucose just going to take up precious space that is better filled with aminos and such for actually rebuilding the damaged tissue? This is where true anabolics come in- ones that are selective to skeletal muscle tissue in the sense of actual protein synthesis like test, other steroids, sarms, etc.

What am I missing here?

 

[jacked.hillbilly]

Mechanism of insulin's anabolic effect on muscle: measurements of muscle protein synthesis and breakdown using aminoacyl-tRNA and other surrogate measures.
Abstract
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.
Google the f in message I can't post links yet

 

[Jimmyinkedup]

Actually I don't think you understand how the whole receptor thing works man. It certainly isn't like you make it sound in your post. At any rate I don't think there is any doubt that insulin is anabolic, its a storage hormone by nature if you will.
The biggest issue or trick with it is trying to make sure muscle is the primary addition that gets stored, not body fat..

 

[zmyj88]

Nah, insulin receptors don't work like that at all. Insulin doesn't give a shit What it stores.

Your body always wants to save for later, energy, muscle, fat, anything that can keep you going when the food runs out or winter comes, or the goddamn herd runs away (thanks ancestors) it's how we evolved.

Insulin gets secreted when glucose spikes in your blood. This leads your body to believe it just ate. The insulin goes in there and says "oh shit, nutrients! Lemme put all this shot where it goes" protein synthesis increases (to build muscle to be later burned for energy, when the aforementioned ice age comes again) and it'll store fat too for the same reason

It also turns off the body's burning of fat and muscle for energy... Because it now senses new nutrients to burn while the stored muscle and fat can remain stored. This is good and bad. It keeps you in an anabolic state, building muscle while keeping the muscle you have, but its also keeping the fat you have, and storing more.

Once you can manipulate your slin, you learn to have high slin periods for storing (trick is to not take in fat here, like NONE), and low slin periods for burning (both fat and muscle) it takes awhile, but youll get the hang of it. Remember, it can only work with what its given to work with.

 

[littleguy289]

Ok that makes more sense in real world shit. I got looking into the actual science just out of curiosity but anything I found led me to question what I already knew.

 

[gorillahung]

I'm type 2 diabetic (shitty genetics). I take Lantus, which is a slowly released insulin where one injection is supposed to last 24 hours. It doesn't really last that long in my opinion. I'm still trying to get it to just keep my glucose levels low let alone use it to build muscle.

 

[littleguy289]

Actually I came up with something else I'm confused about- if insulin keeps you anabolic and out of catabolic, what happens when you're in a caloric deficit?

 

[polarbear1134]

Actually I came up with something else I'm confused about- if insulin keeps you anabolic and out of catabolic, what happens when you're in a caloric deficit?

well not sure about caloric deficit but if you mean what happens if you take insulin when you are staving? would not be suprised if your blood sugar crashes and you pass out.

Diabetics and docs can tell you better but insulin is not something to play with. You need to do it exactly right!

 

[littleguy289]

No I understand all about the risks of hypoglycemia/hypoglycemic shock. I am saying what if you have enough carbs/glucose to keep your blood sugar levels stable but just in a caloric deficit? If the insulin keeps your body in an anabolic/non-catabolic state, then where do the calories to make up the difference come from?

 

[zmyj88]

They don't, it burns the carbs and glucose, when that's gone, you go into shock. This is with synthetic insulin of course, your body knows how much to give you naturally, and it can't tell the difference between its own and what you stuck in your stomach fat. It just assumes that it released all that slin for some reason, so it works accordingly, if the carbs, sugars, and calories aren't there for it, its too late to say "oh shit, that's not my slin, lemme turn this off" its gonna store and burn until it wears off, and if there's nothing left, your sugar drops and the EMTs take over *if you're lucky.
.. Why would you be using slin in a caloric defecit anyway, kinda counterproductive nah?