Question by : carbohydrates and protein synthesis?
Today my teacher said that post workout carbs “unlock” the cell to allow protein synthesis. I know this is over simplified and would like to know the science behind it.
Answer by Confused Dave
There is a hypothesis that net muscle synthesis (which is a balance between the amount of protein being made and destroyed naturally by your muscles) is affected by the hormone insulin. Insulin is a hormone that’s probably best known for it’s role in regulating carbohydrates (dysregulation of insulin results in diabetes), but it has a range of other, more subtle functions in the body, including neurological functions and as an anabolic growth factor. That last one means that when you have lots of insulin, your body builds more stuff up than it’s breaks down, muscles included.
Insulin is regulated by blood sugar, so when blood sugar is low (as when fasting or performing a workout), insulin is low. This is good while you’re doing you workout, because working under low-sugar conditions stresses out your muscles and makes them “want” to grow and improve. The idea is that by dosing yourself with sugar as soon as the workout is over, you’ll raise your insulin levels and improve your net muscle synthesis (mostly by *decreasing* the rate of natural protein breakdown).
I want to flag up that while this is a plausible biological model, it’s still a matter of some debate whether it’s better to just have carbs after a workout, or whether it’s better to have a mix of carbs and amino acids. They key is to get the nutrients into your bloodstream as quickly as possible. But it’s insulin that’s proposed to be the benefit of post-exercise carbs.
I’d also like to flag up that this is suggested as a technique as part of a bodybuilding programme to build up muscle as fast as possible. It’s worth remembering that not everything that builds muscle is necessarily good for your body as a whole, and causing your insulin to spike repeatedly might not actually be something that’s good for you in the long term. If the purpose of your exercise programme is to increase your general fitness, as opposed to building more muscle at all costs, this is probably unnecessary, but as far as dietary supplements for bodybuilding go, it’s probably pretty innoccuous.
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