T Nation

Glycogen Storage

Hi,

If a person is glycogen depleted, then eats a meal of carbs, is glycogen stored first in the liver or muscles?

Or is it simultaneously stored in both?

This:

2nd post from Stu (spoiler:Liver).

You should never get to a state of full glycogen depletion in the first place. If you do, you are doing something very wrong.

[quote]huscarl wrote:
(spoiler:Liver).
[/quote]

LMAO

S

[quote]pcdude wrote:
You should never get to a state of full glycogen depletion in the first place. If you do, you are doing something very wrong.[/quote]

Says who?

Refer here:

[quote]Bricknyce wrote:
Refer here:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC371554/pdf/jcinvest00695-0284.pdf[/quote]

Facinating. I’m not sure I want to try this myself, but I am becoming more and more aware of the importance of fats in our diets. Our ancestors ate very little in the way of carbohydrates, and we managed to evolve as a species nonetheless.

And see some of these too for your interest.

I have more, but these deal with carbo loading after depletion (except for the one by Phinney). These are some of the studies I have reviewed for a report.

Burke, L.M., Angus, D.J., Cox, G.R., Cummings, N.K., Febbraio, M.A., Gawthorn, K.,
Hawley, J.A., Minehan, M., Martin, D.T., & Hargreaves, M. (2000). Effect of fat adaptation and carbohydrate restoration on metabolism and performance during prolonged cycling. Journal of Applied Physiology, 89, 2413-2421

Burke, L.M., Hawley, J.A., Angus, D.J., Cox, G.R., Clark, S.A., Cummings, N.K.,
Desbrow, B., & Hargreaves, M. (2001). Adaptations to short-term high-fat diet persist during exercise despite high-carbohydrate availability. Medicine and Science in Sports and Exercise, 34, 83-91.

Carey, A.L., Staudacher, H.M., Cummings, N.K., Stepto, N.K., Nikolopoulos, V., Burke,
L.M., & Hawley, J.A. (2001) Effects of fat adaptation and carbohydrate restoration on prolonged endurance exercise. Journal of Applied Physiology, 91, 115-122.

Johnson, N.A., Stannard, S.R., Mehalski, K., Trenell, M.I., Sachinwalla, T., Thompson,
C.H., & Thompson, M.W. (2003). Intramyocellular triacylglycerol in prolonged cycling with high- and
low-carbohydrate availability. Journal of Applied Physiology, 94, 1365-1372.

Lambert, E.V., Goedecke, J.H., Van Zyl, C., Murphy, K., Hawley, J.A., Dennis, S.C. &
Noakes, T.D. (2001). High fat diet versus habitual diet prior to carbohydrate loading: effects on exercise metabolism and cycling performance. International Journal of Sports Nutrition and Exercise Metabolism, 11, 209-225.

Phinney, S.D. (2004). Ketogenic diets and physical performance. Nutrition and
Metabolism, 1.

Staudacher, H.M., Carey, A.L., Cummings, N.K., Hawley, J.A. & Burke, L.M. Short-
term high fat diet alters substrate utilization during exercise but not glucose tolerance in highly trained athletes. International Journal of Sports Nutrition and Exercise Metabolism, 11, 273-286.

Sterlingwerff, T., Spriet, L.L., Watt, M.J., Kimber, N.E., Hargreaves, M., Hawley, J.A. &
Burke, L.M. (2005). Decreased PDH activation and glycogenolysis during exercise following fat adaptation with carbohydrate restoration. American Journal of Applied Physiology, Endocrinology, and Metabolism, 290, 380-388.

Check this:

I estimated that a persons average glycogen storage make up about 2500-3000 kcal (right/wrong)?

Would it be a reasonable guess to say that I’d be able to deplete my glycogen stores in one day i I did intense exercise and ate very little carbs?

The stereotypical 70 kg male can store 100 grams in the liver and 400 grams in his muscles. Which I’d guess is 2000 calories. But a “very muscular man” can store up to 1000 grams. No idea how muscular he’d have to be.

And you don’t just use glycogen. Fat and your precious muscle will also be used.

But it’s been said that “you pretty much use all your glycogen in the first two hours of a marathon”, so you’d probably be able to deplete your glycogen stores in a day if you exercised.

varfor du nu skulle vilja gora det

[quote]Theomacho wrote:
I estimated that a persons average glycogen storage make up about 2500-3000 kcal (right/wrong)?

Would it be a reasonable guess to say that I’d be able to deplete my glycogen stores in one day i I did intense exercise and ate very little carbs?[/quote]

Or no carbs.

Yes. You could. It would be hard. The key would be intensity, since low-intensity activities use fat the preferential fuel.

That’s why “carb-loading” for an endurance event is such a stupid idea.

hahaha Bricknyce is my new favorite member, hahaha hes legit and backs up everything he says. You rock bro…dude picks a bone with whoever lol. (I’m a neb but have read since about 08, went thru a phase that I just wanted to get bigger at whatever cost…lol, realized I’ve got the genes to be a runner and will prob make our nats olypic team for london 2012 as a 10000meter/marathoner,) So I gave up the weights, untill this phase is over…Can’t wait to get back at the iron. I’m legit tho and LOVE BBing and will lift and eat my way to fill out my lanky 6’1 frame after the running ends, I LOVE BBing more than anything.

sorry for the rant just don’t want to be judged by my avatar!

I was about to give a little rant about glycogen (3rd year med student, know a little about it) but read his post …lol. nice

Dave

According to Lehninger’s Biochemistry textbook a 70kg male can hold approx .225kg of glycogen via liver and muscle. And my professor, (Phd in Biochemistry, M.s. in Nutritional something or other) uses the figures of 10% of liver mass can be glycogen so 500g liver=50g hepatic glycogen. and 2% of muscle tissue as glycogen (I think it’d be tough to do an actual estimation of “muscle” tissue without DEXA scan).

Since training can affect capacity and etc. So take those above numbers as an AVG for a non training person.

Performing intensive exercise (80-90% of VO2max) has been estimated to expend 150 g of CHO per hour on 70-kg male. In addition brains use roughly 100 g per day, if you are not used to use fat as a fuel. So, if glycogen storages are about 500 grams, then e.g. 2 hours of intensive exercise (plus brain work) and CHO restriction may cause that the stores are pretty much empty even in a day.

kakno, jag vet inte det…

[quote]kakno wrote:
The stereotypical 70 kg male can store 100 grams in the liver and 400 grams in his muscles. Which I’d guess is 2000 calories. But a “very muscular man” can store up to 1000 grams. No idea how muscular he’d have to be.

And you don’t just use glycogen. Fat and your precious muscle will also be used.

But it’s been said that “you pretty much use all your glycogen in the first two hours of a marathon”, so you’d probably be able to deplete your glycogen stores in a day if you exercised.

varfor du nu skulle vilja gora det[/quote]

There are many claims that fasting and restricting carbs does not catabolize muscle. HGH release during fasting is said to prevent muscle breakdown and increase body fat metabolism for energy expenditure.

And concerning muscle catabolism I’m going to test if the theory in the article; “Protein Cycling for Maximum Gains” holds true. I consume MCT:s daily so there will be fuel available most of the time. Also my fat consumption is quite high so catabolism because of energy deficit isn’t something I worry about.

What created my idea to test out a new complex macro-nutrient cycling diet was reading about “the warrior diet”, HGH:s relationship to fasting and a suggestion that Carb cycling might increase glycogen storage capacity. Seems plausible that my body would try to increase storage capacity if I deplete the storages with regular intervals. This is however just a hypothesis.

Now can anybody tell me how fast I can manage to “fill” my glycogen storages?

Sure regular depletion and refilling the glycogen stores with exercise and dietary manipulation would increase the capacity to store CHO. That’s quite well known to happen among those who train/do sports regularly. How fast you can refill your stores depends mainly on how depleted the stores are and how much carbs you are consuming. If the stores are more or less empty, I have seen estimates that 500-700 g of CHO are needed to refill the stores. That’s quite a lot. Also, some of those ingested carbs are used by e.g. brain and energy production in general, so I would quess that the amoung needed would be close to that 700 grams. Personally I have noticed that my stores are empty if I feel crappy; no energy (for pretty much anything, let alone training), brain fog, feeling cold, etc. After emptying the stores, if I go crazy with carbs I may feel good on the next day, but usually I need two days to feel strong.

“Now can anybody tell me how fast I can manage to “fill” my glycogen storages?”

With a traditional carb loading scheme.

[quote]Bricknyce wrote:
“Now can anybody tell me how fast I can manage to “fill” my glycogen storages?”

With a traditional carb loading scheme. [/quote]

Here’s a basic outline on how to properly deplete/load carbs–just posted this over on the BB section:

[quote]Carb depleting and loading is a two-part formula for bodybuilding success. Competitors use this technique in the final week before a contest to create the appearance of a harder, denser and more impressive physiques.

Depriving your body of carbs and then putting the carbs back is an effective approach for two reasons. First, this procedure redistributes water in your body: Water beneath the surface of the skin is shed to reveal deeper cuts and separations. Second, as a bonus, once you load carbs, your muscles are pumped with glycogen(a sugar that is the principal form in which carbohydrates are stored in tissues) which helps to create a fuller look. Here are a few tips that will help anyone to carb deplete and load for maximum gains.

Burn fat before depleting carbs
The objective of carb depletion/loading is to make your physique look lean and muscular, but do not think that manipulating carbs at the last minute will make up for not burning enough fat in the first place. The depletion and loading approach is a complete waste of time if youâ??re not lean enough.

Determine depletion time according to size
Larger bodybuilders(over 190 pounds) can store more muscle glycogen than their smaller counterparts. Its no surprise, then, that it takes longer for the big guys to deplete their bodies of stored glycogen. Typically, larger male bodybuilders should deplete carbs for four-days and load for four days; smaller men require three days to deplete and three to load. Most female bodybuilders require only tow days for depleting and two for loading.
Note that, regardless of a persons size, the depleting and loading phases should be of equal duration.

Deplete, but donâ??t overdo it
Depleting on zero carbs is too sever and can result in a loss of hard-earned muscle mass. A bodybuilder who goes to extremes in carb depletion will often try to recapture lost muscle size by packing in hundreds of grams of carbs. At that point, its too late to minimize your losses.

Cut carbs by 50% during the depletion phase
As you reduce carbs, muscles use up much of their glycogen reserves; your then stuck with flat-looking muscles that are sponge-like. In turn, lowered glycogen levels increase the activity of enzymes that help to form new glycogen when a greater amount of carbs are reintroduced into the body.
The plan of action is as follows: If youâ??ve been eating 300 grams of carbs per day while dieting for a contest, cut back to 150grams of carbs during depletion. A woman dieting on 140g of carbs can easily deplete in two days by consuming only 70g of carbs each day.

Train with high reps on depletion days
High-rep, low-weight training ensures a loss of muscle-glycogen stores without any loss of muscle. Pick two exercises per body-part and do 3 sets of 15-20 reps.

Maintain levels of fat and protein intake
Many bodybuilders increase the number of calories coming from fat and protein sources during the depletion phase. This is a mistake because the body can make sugar from protein, and can use dietary fat for fuel instead od depleting its muscles of glycogen.

Increase carbs by 50% during the loading phase
In the depletion phase, cut carbs by 50%(see the fourth suggestion); in the loading phase, eat 50% more carbs than you did during your precontest diet. Think of it this way: if you eat 300g of carbs during your precontest diet, and you deplete by consuming only 150g of carbs per day, then you should load by consuming 450g of carbs per day. A woman whose precontest carb count is 140g per day should deplete on 70g and load on 210g.

Donâ??t train on loading days
The reason for this edict is quit simple: Training calls upon muscle glycogen for fuel, which will leave muscles looking flat.

Opt for high glycemic-index carbs on loading day one
Glycogen-starved muscles stimulate the glycogen-producing machinery in muscles. On the first loading day, take advantage of this situation by eating carbs that are simple in nature, easy to digest and high on the glycemic index. Examples of recommended carbs include Cream of Rice cereal, white rice, mashed potatoes and sodium-free white bread. Half of your daily carbs should come from these sources. On the other days of loading, you should go with complex carbs(yams; potatoes; long-grain, brown and wild rice), or whatever carbs you relied on during your precontest diet.

Reduce water intake during loading
If you follow the tips to the letter, you will lose water under the skin, because loading carbs into glycogen-deprived muscles require water. Cutting back on the water you consume during carb loading will lead to a fuller and tighter appearance. Reduce your intake of water by 50% on the days you load carbs.

Author: unknown[/quote]

Glycogen stores can be depleted a lot faster than replenished, right? If so wouldn’t a 2 days depletetion followed by 3 days loading make more sense than 2 days depletion and 2 days loading?

Or should i trust that I’ll learn to feel when my glycogen levels has peaked?

I think I’d be able to deplete my glycogen in 2 days since I have had days with almost no carbs and they’ve worked out just fine, so during depletion days I will use almost no carbs.