Glycogen:

How to Use Glycogen Loading to Avoid Getting Fat or Flat

By Ori Hofmekler
Author of The Warrior Diet

Glycogen replenishment is a key to full muscle recuperation from prolonged or intense exercise. Any failure to replenish glycogen stores is typically associated with "flat" muscles, plus a loss of strength, speed, velocity and the capacity to resist fatigue.

The most common glycogen restoring method involves a few days of carbs depletion (very low carb diet) followed by a few days of carb loading (high carb diet). Known as carb loading, this method is generally used by long distance runners. The goal of carb loading is to pump maximum glycogen into the muscle tissues and thereby grant maximum stamina for an increased competitive edge. Endurance athletes can benefit from carb loading by virtue of a substantial biological increase in muscle capacity for glycogen loading following a period of glycogen depletion.

Nevertheless, this method of carb loading raises some serious questions, in particular for bodybuilders. First, how many days of carb depletion are required? Second, how many days of carb loading are required? Third, how much carbs should one consume during carb loading? Fourth, how to incorporate carb depletion without wasting muscles? Fifth, how to incorporate carb loading without gaining fat?

Let's briefly address the above questions.

Carb depletion

Muscle loses its initial glycogen storage within 10-30 minutes of sustained intense exercise, (depending on the level of intensity and pre-exercise glycogen stores). Glycogen is the main fuel for fast muscle fibers (strength, speed, and velocity) and could be rapidly depleted during resistance or sprint intervals. Ten minutes of all-out sprint intervals or sustained resistance training can burn more initial glycogen stores than an hour of moderate jogging. Thus, a bodybuilder or an athlete who is engaged in 30-60 minutes of vigorous workout can effectively deplete initial muscle glycogen stores within one training session.

Carb loading

Bodybuilders and strength athletes can take advantage of post-exercise muscle peak capacity to replenish glycogen stores. Incorporating proper recovery meals right after exercise can literally grant full glycogen replenishment within only a few hours. Studies at the University of Guelph, Ontario, Canada, demonstrated that the net rate of glycogen resynthesis is highest in the first 30 minutes of recovery, and then it significantly decreases by 62% throughout the remaining 4.5 hours of recovery.
 
One way to effectively ensure glycogen loading in the muscle tissue is by incorporating a some sequenced recovery meals-every 60 minutes right after exercise. Each meal should consist of 25-30g of carbs and 15-30g of protein. That way, four small recovery meals can provide 100-120g carbs for glycogen loading to the muscle tissue within 3-4 hours-with a bonus of up to 120g of amino acids. By applying small meals, one can avoid too great an insulin spike, which will trigger undesirable fat gain.

Bodybuilders and athletes should never overlook the importance of glycogen replenishment. Recent studies at the RMT University, Bundoora, Australia, proved again that glycogen stores in the muscle positively affect the muscle's capacity to generate energy and sustain intense performance. Individuals with high muscle glycogen have a higher capability for energy expenditure than these with low muscle glycogen.

Saying that, there are still some concerns regarding the effects of carb depletion and carb loading on muscle gain or fat gain, respectively. Strength athletes including bodybuilders cannot afford using the same glycogen loading methods as endurance athletes. A few days of carb depletion may be a few days too many (too restrictive) to the muscle, leading to loss of muscle mass and strength. It makes more sense then to incorporate instead shorter cycles of glycogen depletion-loading, on a day in, day out basis.

For instance, one can incorporate one day of low carb followed by post-exercise carb loading the following day. Even so, to avoid muscle waste during a low carb day, it's highly recommended to increase fat consumption for that day, thus compensating for the missing carbs with fat fuel.
 
Incorporating short glycogen loading cycles with small recovery meals would also help reduce the risk for fat gain often associated with a prolonged period (few days) of carb loading. Recent studies at Hadassah University in Jerusalem, Israel showed that prolonged and frequent carb feeding may cause over secretion of insulin (hyper-insulinaemia). Leading to insulin resistance and a myriad of metabolic problems, including an undesirable fat gain. To avoid this, one should take advantage of a post-exercise small recovery meal to provide a swift full glycogen loading with no side effects.

In conclusion, for a bodybuilder or a strength athlete, glycogen loading is a tricky skill. If carb loading is done too long or too late, one may get fat or stay flat. Intensely trained individuals should take advantage of post-exercise muscle peak capacity to recuperate and restore glycogen by applying small, sequenced recovery meals right after exercise and thereby prevent insulin resistance and fat again.
 
Muscle initial glycogen loss can average between 300-500 calories (about 80g-120g) within 30-60 minutes of intense exercise. Therefore, 3-4 recovery meals consisting of 25-30g carbs each could be sufficient enough to provide a substantial glycogen loading, with a full muscle pump and potential for explosive performance.

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