All About Glycogen

I bet you've all had them.  Those days when you drag yourself to the gym, and for some reason can't lift even fractions of what you normally could.  You'll end up frustrated beyond belief at the end of your session, wondering why weights that you generally pull with ease just won't budge.  You may look in the mirror, and feel as if your muscles looks smaller, softer, and less "bulky" than they usually are.  You just may feel weak, a shadow of your formal, beastly self.  Why has all your progress suddenly come to naught?

The answer?  Glycogen depletion.

Glycogen is an extremely important substance that is stored in your muscles and in your liver.  It is the body's usable source of carbohydrates.  You've always wondered how all that food you ate ended up as usable energy.  Well, glycogen is the answer!  Your body basically converts ingested carbohydrates into glycogen, and saturates your muscles and liver with the stuff to use as an efficient and powerful fuel source.  Hence, after your workout (in which you've hopefully depleted a large amount of your glycogen stores), it would definitely be in your interest to consume carbohydrates with your protein (the ratio is under scrutiny, some say 2:1 carbs to protein, others say as much as 4:1) in order to initiate both protein and glycogen synthesis.  

Easy enough right?  To keep those glycogen stores topped off, keep some carbs in that post-workout meal.  But because you've read my other articles (you have, haven't you?) , you may, upon considering this information, have reached a quandary about replenishing glycogen stores.  You may have realized that there are multiple types of carbohydrates (namely simple, and complex).  So which does a better job of fueling up those muscles after a hard workout?  Or maybe you're wondering if it matters at all, as long as your muscles get those much needed nutrients.

Well we've established in previous examples that IN GENERAL complex carbohydrates are a more effective energy/nutrient source for your body.  They are released slowly and used efficiently, and are less likely to be stored as fat.  They'll give you lasting energy for long periods of time, and are the better choice for filling up those glycogen starved muscles.  Why aren't simple carbs quite as good?  Well here's a quote from a website I found that describes it better than I could:

"… complex carbohydrates … are more effective in replenishing glycogen stores than simple sugars. This makes sense because complex carbs are released slowly whereas simple sugars are released very rapidly, potentially overwhelming the glycogen synthesis pathways and "spilling over" into fat stores. Furthermore, the increased insulin release resulting from simple sugars causes more of the sugar to be converted to fat (Parillo, p.20)."

So there you go, glycogen stores are more effectively replenished via complex carbohydrates.  Good examples of easily consumable complex carbohydrate sources are maltodextrin and brown rice syrup, both of which can easily be mixed into a post workout protein shake.  

Brown Rice Syrup...lovely isn't it?

But simple, sugary carbs also have their place post workout.  In fact they play a very important role in initiating both glycogen and protein synthesis.  Simple sugars (like dextrose, a commonly used sugary carb in the fitness scene) will quickly spike your blood sugar, which allows muscles to rapidly absorb all sorts of nutrients.  In fact, post workout is about the only time you really want to voluntarily "spike" your blood insulin because it allows for all that good synthesis material such as amino acids, carbs, vitamins, minerals, you name it, to be sponged up by those soft, tired muscles in no time flat.  Pretty nifty biochemistry, if I don't say so myself.  

There it is, a simple explanation of muscle glycogen, and why it is so crucial in the strength/fitness scene.  Low glycogen levels=poor performance, and believe me nobody wants to feel like crap in the gym.  If you've come off a long training cycle, chances are your glycogen stores are very low.  Don't be afraid to take a day off and eat a good amount of quality carbohydrates.  Everybody needs a re-feed every now and then!

Keep those muscles fueled, lift heavy and run like the wind.  Good luck!

Reference Article (A great read if you have the time, delves into more complex topics about glycogen replenishment):  http://fitnessforoneandall.com/nutrition/article/glycogen.htm