Replenishing muscle glycogen

by glycogen I mean glucose sorry got the two confused.

Replenishing comes from the amount of gluclose you ingest. The answer might be in your diet. There is some truth to carbo loading. Also, when body glycogen is depleted in a long run, it has to be replaced through food. It usually only takes about 24 hours or so to fully recover, maybe a little bit more. Thats just the basics. Hope that helps to answer your question. I've got more info if you want it.

Are you British, by any chance, YR?

yeah I am half British, quarter German, and another quarter Irish, But what does that have to do with anything.

I do everything I can to eat carbs, I would find it difficult to eat anymore.

Yeah I would also like more if it is not to much to ask.

Ok, this may get a little disorganized but here goes. The amount of glycogen that can be stored in the body is limited. Most of this is found in the liver, some in the skeletal muscle, and a small amount in the blood stream. There is enough glycogen stores to last the average person about two hours worth of running. The body doesn't completely rely on just glycogen though. Fat is the body's largest energy source, but the hardest to break down. At faster speeds fat can't be utilized quick enought to provide enough energy so glycogen is used. Some thing the better runners are better able to break down fat to use as energy.

Carbohydrate storage in the body can be increased through training. The carbohydrate stores in leg muscles are greater in trained people than untrained. The legs also contain more stored glycogen than the arms or a runner because the legs are more highly trained.

The amount of glycogen used by the body depends on the intensity of activity. Most glycogen is lost through the slow twitch muscles. Continuous exercise at 70-80% of VO2 max also depletes muscle glycogen more rapidly.

Athletes who eat high-carb diets can usually restock their glycogen stores in 24 hours. Complex carbs work better to restore glycogen. 525g a day or more of any carbs work the best. Fructose doesn't really help any. Really loading up on carbs (like doubling amount) doesn't help either. Studies have shown that glycogen resynthesis was quicker if done immediately after exercise.

Those are the basics on glycogen stores and replenishment. Just taking the info you gave, this may not be the problem for you. There are many other reasons for fatigue from day to day that have a little to do with this but more with other things. This will probably answer your questions about glycogen but you'll have other ones. Let me know what you think. I'll be happy to give my opinion some more.

I would have to agree with ya cyron10k about the replacing of carbs after a run, but there was a very important piece of information that you forgot to mention about the study. In replacing the carbs after a hard workout the body "takes" in glucose faster if the carbs are taken in within 2 hrs after the workout and the closer it is to right after the workout the faster the glycogen/glucose will be replaced.

meis, you were close. Food needs to be taken in within 20 minutes of the cessation of exercise in order for glycogen replenishment to be most efficient. If you wait too long, it could take as long as 48 hours to fully replenish your stores. Best thing to do is eat some sort of carbs within that 20 minute window, then get the rest later that day. Cyron10k is mostly right with what he/she said as well. A few little mistakes, but I guess nothing to really make too much of a difference. Don't forget that hydration and sleep make a big difference with fatigue as well.

I dont how how any of that other shit is supposed to help you dude.

This is what I think. After training when the muscle is depleted of its energy source, it requires replacement of glycogen, to return or maximise its potential. The soreness you are feeling is a mild state of what is called ketosis. This is where your body is naturally trying to replace the glycogen - but there isnt any. So it uses body fat. This is how some smart entrepenurial people tell stupid fat people they can lose weight.

Anyway, the key is rapid replenishment. It has been scientifically found that there is a "window" of time post training where if glycogen is restored and metabolised, you can actually INCREASE the potential amount of maximum muscle glcogen your muscles can store.

So, this is how I would do things. Keep in mind, that in this situation, complex carbohydrates are pointless, as they take well over an hour to metabolise. The only way you are going to "load your weapons" is by taking on simple carbs - or sugars. You can do this in a variety of ways. Like Gatorade, or a sports drink that include electrolyte. But the best one is just a white bread roll with a banana. But really anything sweet. Chocolate bar, couple of suckable lollies. Hell, I was stuck one day after a race with nothing to take in, so I went back on my morals, bought a Coke, shook the bastard up so it had no gas, and drunk that - perfect.

Im sure that you knew already the food you should be taking. But DONT be afraid of simple sugars. A lot of runners are for some reason. Only fat people and diabetics should be. But I emphasise the timing. Immediately is best, and the closer you get to this, the more you will physiologically maximise your potential.

Hope that helped.

Maybe your sore muscles need a top-up in protein too?? (this doesnt need to be taken so immmeditaly - in fact its better not too)

So - quarter German eh...

sprechen sie Deutsch? oder sind sie ein doof schvule??? ;)

(if you can understand - just kidding)

isn't that what we were saying above?? replace you glycogen with carbs asap after a hard workout. I just had physiology of exercise class and we spent a good day talking about carbo loading and i'm not declaring myself as an expert. And I'm not trying to start an argument here as I think this is an excellent thread.

A lot of very good points on the subject. I would just like to add one thing to the mix. I apologize if someone has said this already, I didn't read every post:

Glycogen replenishment is quicker following intense anaerobic exercise. The reason being is that lactate and pyruvate (by products of anaerobic glycolysis) are catalysts in glycogen resynthesis. Therefore, glycogen will be resynthesized faster if the extent of the work is anaerobic. This is why most middle distance runners don't need a high carb. diet.

Further, glycogen is resynthesized fastest if you cool-down at 50-60% of VO2 max and even faster if you do some sort of intermittent exercise (such as 6x100m turn-arounds).

However, for a middle-distance runner, you won't get into considerable glycogen depletion unless you run for more than an hour, and even then, it would have to be pretty fast. Moral of the story, don't worry too much about glycogen depletion/replenishment. Follow the simple rules laid out by the other posters (cooldown slow, ingest some sort of carbs quickly after the end of the workokut). When in doubt, have a glass of gatorade or orange juice. there's more than enough glucose in there to suit your needs.

If you want all the details plus a ton more, I suggest you shell out about $15 for a really good sports nutrition book. I like Nancy Clarke's Sports Nutrition Guidebook (Human Kinetics). It explains everything and includes a ton of recipes as well. Money well spent.

"Further, glycogen is resynthesized fastest if you cool-down at 50-60% of VO2 max and even faster if you do some sort of intermittent exercise (such as 6x100m turn-arounds)."

If you continue exercising - you will continue glycogen depletion. That is why there are coaches who would rather have there athletes warm down for a very short duration, and then ingest CHO to begin resynthesizing the glycogen stores, rather than follow an intense workout with a prolonged warm down and continue the breakdown of glycogen stores.

Very interesting thread!

The two keys to rapid glycogen replacement are (1) the

amount of carbohydrates ingested, and (2) the timing of

your carbohydrate intake. Regarding (1), even if you

are "eating all the time" you may still not be getting

enough carbs - count up the grams of carbohydrate you

eat each day. If you are training hard you need 3-4g

of carbs per pound of body weight per day, and if you are

carb loading for a long run or long race, bump it up to

5g/lb for 3 days prior to the race. This is a lot of

carbs, and if you are eating a lot of bulky high fiber

food you may find it tough to get this much in - resort

to drinking carbs (e.g. gatorade, juice, whatever), or other easy to digest carbohydrates (e.g. sugar, honey) if you need to get in what you need. Fruits, veggies, and complex carbs are all good things to be eating, but you may

not be able to eat enough of them - don't be afraid to resort to eating some quicker carbs on top of your healthy diet. You may also need to cut back on fats (even good

ones), simply because they can make you too full to eat

enough carbs.

Regarding (2), people have already mentioned the importance

of eating as soon as possible after you run. Try to get

carbs in within the first 15-30 minutes after you run - say

1/2g carb per pound of body weight, and the same again an

hour later. In addition, try to eat frequently throughout

the day, every 2-3 hours, rather than eating big meals.

There is some very good information in this thread. As was pointed out, you will facilitate loading carbs as glycogen in your muscles if you ingest some SIMPLE sugars almost immediately following a depleting workout (this raises insulin levels, which is a major contributor toward loading those carbs), THEN eating a meal rich in COMPLEX carbs about an hour or so later (less than two hours post-run). Make sure you get enough WATER, as well, since carbs cannot be stored as glycogen without adequate water (but you say you're well-hydrated, so I doubt that's a problem).

I generally only recommend taking those simple sugars following long runs or moderately long tempo efforts. CHRONIC ingestion of simple sugars can have some deleterious effects which contribute to cellular inflammation (via the arachidonic acid cascade) and which can lead to increased risk of free radical scavenging.

If you need free GLUCOSE, you can eat grapes (even in the middle of a workout). If you're on a long-ish run, you can carry some grapes in a small plastic bag and nibble one or two every few miles. Some people do get side stitches from the sudden addition of glucose during exercise, so experiment with this to see if it will work for you. Some people take glucose tablets during long outings or even during marathon races, since liver glycogen (which provides blood-borne glucose to sustain brain function) falls during those very long runs.

One poster alluded to the fact that glycogen resynthesis is faster following anaerobic exercise. Part of this is due to what is knwon as gluconeogenesis, in which lactate is reconverted to glucose in the liver. Armed with this imformation, we've found that some runners benefit by a slight shift in favor of dietary protein during a stage of the season in which their mileage is lower and they are focusing more on speedwork. But as long as you are doing longer aerobic work, you will obviously need a little extra carbs. Don't neglect FATS in your diet, either. You need to eat fat in order to metabolize fat. Fish oils and Extra Virgin olive oil are excellent sources of essential fatty acids.

The same poster alluded to the importance of a cool-down and the possible inclusion of short strides in the middle (or near the end of) that cool-down. Those strides are very effective if done after a moderate to hard continuous TEMPO run (this practice re-elevates the heart rate and allows for conversion of lactate into pyruvate), but they can also be included at the tail end of a long run.

Anyway, I don't know if all this information will be of much use to your particular situation. If I remenber, I'll ask Kyle Heffner about what might be going on with you. He's very well versed in the area of nutrition for athletes and may have some good input (if it is something which is correctable through diet).

Thanks for the input everyone.

How about chewing a whole pack of Bubble Yum during a long run? Perhaps two in sequence, switching flavors if necessary? I am not kidding. That and some water and you're set if you're not prone to the "sugar stitches" mentioned. Just remember to brush your goddam teeth after every run, and to floss your ass.

meis wrote:

isn't that what we were saying above?? replace you glycogen with carbs asap after a hard workout. I just had physiology of exercise class and we spent a good day talking about carbo loading and i'm not declaring myself as an expert. And I'm not trying to start an argument here as I think this is an excellent thread.

no fair call - my bad...homey... In all honesty I read the first posts and made my judgement off that. All apologies. However, I do point out, that the TYPE of carbohydrate is important, something which you did overlook. I think its fair to say, that when most MD-LD runners talk about carbs - they are talking about rice, pasta, grainey breads etc etc. Runners - dont be afraid of the worlds sweety goodness - esp after the long run (just brush your teeth and floss...son...) ;)