Today I would like to examine the idea that carbohydrates are necessary for proper muscle function. There are two "basic truths" everyone who works out has heard:
- We need carbohydrates in order to expend energy. All athletes "carb up" for the big marathons and according to mainstream nutritional science, protein can be converted to carbs if needed. However, that's slower and hard on your liver. So if you really want to impress your friends, better start your workout with an oatmeal.
- Even my Crossfit coach agrees with this one: carbs are great for a post-workout recovery.
When I reviewed studies citing this one - I learned that
- Essential amino acid and carbohydrate ingestion before resistance exercise does not enhance postexercise muscle protein synthesis
- Protein coingestion stimulates muscle protein synthesis during resistance-type exercise
Word of mouth among Crossfit trainers says, no. But thus far I have not been able to find very much evidence. Can you point me in a good direction?
The above makes a slightly different implication than my point. Muscle function and the central nervous system are going to get energy from carbs, but your liver can produce them from proteins if it must. It's an expensive use of protein, and it seems it would be better to replenish those with carbs as that usage is preferential to storing carbs as fat, etc.
ReplyDeleteYes, I agree. I mentioned carb conversion into protein in #1 above. I am not convinced about the argument that this use of protein is "expensive" in a high-protein diet. You would have to show that, if one consumes so much protein that they lack carbs, the conversion to protein would have such a low yield, that less protein is available for other functions than before.
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