Sport Diet macronutrient composition. Theory and questions

[Karky]

I hope to make this into a good discussion about nutrition. While experience based answers are welcome, I would very much like some scientific answers aswell. Why is it so? etc.

Assuming bulking and wanting optimal performance

So the way I see it you need enough carbs to have filled your glycogen stores by the time the next workout starts
You need enough protein to build muscle, enzymes, etc, but there is no point in more.
You need enough fat to, what? transport fat soluble vitamins, make cell walls, etc. (more?)

but when you've covered what your body needs, you still need to make out a surplus. What macronutrients should that consist of? If I eat enough carbs to fill glycogen stores, is there any point in eating more carbs? Will a surplus of carbs somehow lead to better muscle:fat gain ratio than a surplus from fat? (this is where some people say yes and point to that dietary fat is very similar to body fat and thus it is easy for the body to store it as fat, while storing carbs as fat requires more effort, true, false?)

On the glycogen thing. How much of carbo is needed to replenish glycogen? If we assume a person has 500g of glycogen storage capacity (400 muscle, 100 liver) and he trains until that is depleted as much as it can get depleted. He then wants to replenish them before his next workout which is 48 hours later. Surely, he can't just eat 500g of carbs over the next 48 hours and expect it all to go to the glycogen stores, can he? I understand there are probably a LOT of variables here.. But I would very much like to see a discussion.

 

[i_love_muscle]

On the glycogen thing. How much of carbo is needed to replenish glycogen? If we assume a person has 500g of glycogen storage capacity (400 muscle, 100 liver) and he trains until that is depleted as much as it can get depleted. He then wants to replenish them before his next workout which is 48 hours later. Surely, he can't just eat 500g of carbs over the next 48 hours and expect it all to go to the glycogen stores, can he? I understand there are probably a LOT of variables here.. But I would very much like to see a discussion.

If you are in a glycogen deficit position, I would assume that initially your body would first suck the glucose out of the food, and then once you had established homeostasis, the excess glucose would be converted to glycogen and stored. Moreover, the carbs you ingested would need to used as energy to convert glucose into glycogen to be stored in your liver because that's your brain's back-up fuel tank. So you would need more than 100g, simply because you are in a deficit and going ketotic and 100% of your carb intake is not immediately converted into glycogen (because you need fuel to do that, so you will theoretically be using your carbs to convert said carbs into glycogen as previously stated).

Amino acids and fats can be converted into glucose, but it takes more energy than converting carbs into glucose.

Glycogen stored in muscle tissue is only good for muscle tissue. It's not able to be distributed anywhere else. So your muscle tissue would get the glycogen stores after your brain and liver were satiated.

Theoretically speaking, of course

Don't know if I've made any sense ... my mind isn't working too well today. I've got the flu

 

[Karky]

It would take 100g of carbs just to get it started? that seems a bit high, doesn't it? there isn't a lot of glycose in the blood. So I'd think reaching homeostasis would be done pretty quickly (if you ever went out of it, the body has a tendency to make glycose from protein if blood glucose gets low).

 

[i_love_muscle]

True enough. Your body can even make glucose out of fat. But it's not very energy-efficient.

I still think you'd need more than 100g because your body would want to use the immediate source of energy (i.e., what you're eating) over the more energy-intense method of utilizing protein tissue.

But you would probably want to start out with about 35-50g to see where that got you.

I'm just thinking about what happens to me if I go severely hypoglycemic. I often have to ingest 150gm of carbs in 30 minutes just to get me back to where I was before (i.e., to stabilize my blood glucose). That's a lot of carbs. And that's without taking any insulin.

So yeah, I think you'd need a lot more to re-establish your glycogen stores.

 

[Karky]

yeah, more than 100 to fill glycogen stores. but to start filling them. You're making it sound like the first 100g of carbs will have no effect on stores. So where does it go? Blood glycose won't be at 0, so not a lot of carbs will have to get blood glucose up. And after blood glucose comes glycogen stores.

 

[i_love_muscle]

No, what I mean is that you would need more than 100g to replenish your glycogen stores because you'd be using some of the 100g of carbs to convert the CHO into glucose/glycogen.

Does that make any sense?

 

[Karky]

yes, I get that. Of course 100g of carbs won't be enough to replenish 500g of glycogen even if all the carbs went straight into the stores (which I get that they don't)

Anyways. I know after training insulin sensitivity is high and a lot of the carbs you ingest will be converted to glycogen. But after that, how much of the ingested carbs will get turned to glycogen? is it pretty much all the glucose that is not needed to keep blood sugar within normal range minus what you need to fuel the conversion? If so, to replenish 500g of glycogen you wouldn't need that much more than 500g between the workouts, maybe like 600-700? And you'd have 48 hours to do it (assuming you train to glycogen depletion every 48 hours)
Then of course, most people who train with weights probably don't deplete their glycogen stores completely.

 

[i_love_muscle]

Exactly. My understanding is that once the blood glucose and liver glycogen stores have been replenished, the rest goes into the muscle tissue. Any leftover will be stored as fat.

If you are in a glycogen deficit, you'll want to eat high GI carbs. But it can take quite awhile for the muscle glycogen stores to be fully replenished.

Your glycogen stores equal about 1800-2000 calories of energy. So don't you think you'd have to ingest at least 450gms of carbs to fully replenish your stores if you were totally depleted or in a deficit? (Because 1gm of carbs is about 4 calories, give or take.)

I was searching for some science, and I came across these:




Not sure whether this is what you're getting at ... are you more concerned with muscle glycogen storage or glycogen loading? Are you thinking about Astrand's regimen?

 

[Karky]

I'm just thinking about replenishing glycogen before the next workout. I'm just wondering how many carbs you would have to eat in order to do that. If almost all carbs will go to glycogen until it is full then great, that is the answer I'm looking for, since that means you will just have to eat a bit more carbs than your glycogen stores can handle (a bit more since it takes some energy to convert it), how much glycogen the stores in muscle can handle will depend a bit on the person.

But I sorta doubt that is the case, maybe in the first hours after training when your glycogen stores are very low, but as they start to fill up, will this still be the case? I don't know. I hope someone very knowledgable in physiology can chime in..

 

[[Focus]]

Don't mean to nitpick, but what kind of training would you be doing where you tap your body's entire stores in one session?

Aside from that, I agree roughly with what i_love's said thus far. With the above addendum taken into consideration, 100g'ish (simple carbs with about half as much protein) immediately after, wait approximately 2 hours for that to get did, and then another 100g (complex carbs with about half as much protein), wait another 2 hours and do another 100g (complex carbs with about half as much protein). Assuming you've really kicked the **** out of yourself training strength (and nothing else, mind you, hence my earlier question) for as much as an hour and a half in the gym, this would be more than adequate to compensate for glycogen depletion. Which is why, I imagine, it correlates roughly to the anecdotal wisdom.

2 hour intervals because it is also suggested that most people are capable of processing roughly 400 kcals cals per hour, and we are speaking of generalities. I myself am able to process a great deal more, and am currently timing appropriately.

 

[Karky]

I just used the fully depleted as an example, It would probably be more interesting to find something for less than fully depleted, since most people don't train until they are completely depleted (if you did you'd know. People who talk about hitting the wall have usually run out of glycogen)

 

[Phee]

Quick question, If I am weight train on tuesday, wednesday and friday, intense lifting but I am in the middle of dropping fat, should I be worrying about restoring my glycogen storage? I usually have a 1/2 cup of rice and 2 pieces of lean, skinless, boneless chicken after a workout.

 

[tjl]

Don't mean to nitpick, but what kind of training would you be doing where you tap your body's entire stores in one session?

Presumably doing endurance events, where running out of glycogen leads to "hitting the wall" or "bonking" with significantly reduced performance with extreme tiredness.

 

[[Focus]]

Presumably doing endurance events, where running out of glycogen leads to "hitting the wall" or "bonking" with significantly reduced performance with extreme tiredness.

Yeah, this is what I assumed Karky to mean, but as he says real world wise, this is not exactly frequently applicable. In that case though, what i_love said pretty much stands. Most of the literature supports the idea that at such a point, the body can and almost certainly will use "α" almost exclusively for replenishing total glycogen stores where "a" = g of carbohydrate above that amount which is required to meet current metabolic needs and "β" = g carbohydrate required to meet current metabolic needs.

Trying to determine the absolute values of such numbers however is (in the general sense, and to my mind) almost entirely useless as, pursuant to a dynamic similar to the above correlation, and barring the implementation of an unlikely and rather revolutionary algebraic model, having applicability only to the individual.

 

[[Focus]]

Quick question, If I am weight train on tuesday, wednesday and friday, intense lifting but I am in the middle of dropping fat, should I be worrying about restoring my glycogen storage? I usually have a 1/2 cup of rice and 2 pieces of lean, skinless, boneless chicken after a workout.

This is not at all a quick question. Neither is it complete or on-topic. Please consider asking it in the appropriate locale.

 

[Phee]

This is not at all a quick question. Neither is it complete or on-topic. Please consider asking it in the appropriate locale.

How is it off topic?

The main post is about glycogen storage and was wondering if I should be worried about mine for my next lifting session if I am trying to lose weight.