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F1eld
10-06-2008, 01:09 PM
1. generally..how many grams of carbs can be stored in your muscles as glycogen? im assuming that it depends on how much muscle you have, but in this situation lets assume a 175lb @ 10%bf male.

2. How long does it take for carbs to be transported and stored as glycogen from the time of ingestion? And does it depend on its glycemic index value? Lets say i ingest 60g of oatmeal, how long does it actually take for the glucose from that food to actually be stored in my muscles?

in10city
10-06-2008, 01:35 PM
1. generally..how many grams of carbs can be stored in your muscles as glycogen? im assuming that it depends on how much muscle you have, but in this situation lets assume a 175lb @ 10%bf male.

2. How long does it take for carbs to be transported and stored as glycogen from the time of ingestion? And does it depend on its glycemic index value? Lets say i ingest 60g of oatmeal, how long does it actually take for the glucose from that food to actually be stored in my muscles?
The amount you can store varies with muscle muscle mass, muscle conditioning, etc... But an "active" 150 lb. man can store ~2000 calories - 1600 of which are stored in the muscles as glycogen where they can be used directly; 320 calories are stored in the liver as glycogen where they can be released into the bloodstream; and 80 calories are stored in the blood as glucose and can travel to where they are needed. 15 g/kg is another number I've seen from a massive carbohydrate overfeeding after depletion.

You can expect a bit more than this.

The other answer is more involved. The rate will potentially vary depending upon timing, nutrient status, glycogen levels, etc... and it may not all be stored. I'll fill this in later if someone else doesn't chime in.

F1eld
10-06-2008, 02:20 PM
*bump*

people should be interested in this

IronBrendan
10-06-2008, 03:34 PM
The average Joe stores about a pound (454g).

The more muscle mass one carries though, the more glycogen they can store (naturally).

The 15.7 x (LBM in kg) is a good starting point but you have to remember that LBM includes not only muscle but bone and other tissues as well.

I've seen studies that say it takes about 24-48 hours for storage to take place. It would obviously depend on the state of the individual as well as metabolism, type of carb etc.

www.ironbrendan.com

reefpicker
10-06-2008, 09:41 PM
I am not sure where you are headed with this questions, and perhaps you should have tried to at least say what issue you are trying to address here. For example, do you want to determine the best time to have a pre-workout meal? For that, I suggest checking Alan's sticky on PWO and PoWO meals/shakes.



2. How long does it take for carbs to be transported and stored as glycogen from the time of ingestion?

If you count from time of ingestion, well, it depends on what you eat. Fats slow down ingestion of carbs/proteins, which is why they are not recommended for Preworkout meals and shakes.

Food goes to your stomach, where it can spend a few minutes to 30 mins, again depending on what your meal is.


Carbs are then digested and absorbed in the intestine (duodenum for the most part). The process of digestion begins in your mouth, as amylases in your saliva start breaking the carbs up. However, most absortion takes place farther down in the duodenum, etc.

Keep in mind also that the stomach will actually empty its contents in pulses (gastric emptying) to the duodenum and that fats, even when they kind of slow down the process, are usually floating on top of the stomach, so that they are often the last to be digested (while the carbs would be first). Of course, I do not believe this is a golden rule... But it is physics, so maybe it is... :)

In any event, if I had to guess, I would say 15 to 30 mins for a simple meal to go from your mouth to your duodenum. Then I would add another 10 to 30 mins for the starches to be broken down an absorbed.

Now, those starches will go as glucose into your blood, perhaps fructose too.

Then you go from that to gylcogen, depending on your body's need for energy and its hormonal "milleu" at the moment of digestion (is cortisol high? are you in a fasting state?).

In general however, your glucose will be sequestered by the liver as glycogen or by the muscle as glycogen, if and only if, insulin is around.....


And does it depend on its glycemic index value?

The glycemic index value is a measure of how long the glucose peak lasts after a meal.... The longer it lasts, the less insulin is being sustained in plasma, and the less glycogen is being produced.. So in a way, the answer is yes. However, keep in mind that digestion is a big part of this whole thing. I am quiet sure that the human body can convert glucose to glycogen in a very fast and efficient manner.



Lets say i ingest 60g of oatmeal, how long does it actually take for the glucose from that food to actually be stored in my muscles?

Oatmeal is high in fiber, or carbs that are a bit harder to digest but do pass quickly to thru your intestine... My guess is that if a PreWO shake takes from 30 to 1 hour, a cooked oatmeal will take a similar amount of time, perhaps just a bit more, since its cooked (whole oats). But to be honest, this is a guess.

The graph in wikipedia's GI discussion seems to suggest this time-frame is not at all unreal: http://en.wikipedia.org/wiki/Glycemic_index


And that graph brings me to my final point: Keep in mind that digestion is a process, and although it may peak at 30 or 60 mins, the complete digestion and absortion of ALL the food you ate, may take twice that time!

-Aaron-
10-06-2008, 10:57 PM
The average Joe stores about a pound (454g).

The more muscle mass one carries though, the more glycogen they can store (naturally).

The 15.7 x (LBM in kg) is a good starting point but you have to remember that LBM includes not only muscle but bone and other tissues as well.

I've seen studies that say it takes about 24-48 hours for storage to take place. It would obviously depend on the state of the individual as well as metabolism, type of carb etc.

www.ironbrendan.com

Did you just pull that number out of your ass?