Muscle Glycogen And Athletic Performance

Muscle glycogen is a key player in an athlete’s success. Glycogen provides rapid energy release when the brain sends out signals to any muscle group to contract forcefully and quickly.

Therefore, high-intensity exercise that requires quick bursts of explosive movement requires a large and readily available glycogen pool to be stored in the muscles.

Glycogen is an energy storage molecule found within muscle cells.

The shape of glycogen is similar to that of a Mexican hat or sombrero, which gives rise to its name, “glyco-” which means “sweet,” as it is used for energy, and “-gen,” which means “create,” referring to its ability to be converted into glucose when needed.

The body can only create glycogen through carbohydrate consumption or conversion from proteins.

This sustains an elevated blood sugar level that stimulates insulin production to provide glycogen storage sites inside muscle cells for energy when needed.

Glycogen stores are the muscles’ fuel reserves, allowing for quick bursts of movement that require sudden bursts of energy to contract muscle fibers with high intensity.

Because it is stored outside the cell (as opposed to fat which is stored inside), glycogen can be broken down quickly by enzymes into glucose or sugar, which is transported into the cells to create energy for cellular metabolism.

What Is Muscle Glycogen?

Glucose and glycogen are complex carbohydrates whose structure is composed of chains of glucose molecules.   These can be stored in your muscles or liver as energy for use within minutes to hours, depending on when you need them most.

To get these glucose and glycogen molecules, your body first breaks down carbohydrates into their simplest and most basic unit, glucose.

Carbohydrates are composed of chains of 1, 2, or 3-ring sugar molecules (monosaccharides) in various combinations with one another arranged into rings, branches, or long straight lines.  

To get the energy you need to power your muscles and organs, sugars must be broken down into their glucose molecule single ring form.

The body breaks down carbohydrates or glycogen (same thing) into glucose to provide cellular energy for immediate use. However, it can also convert the excess glucose molecules into storage units of starch known as glycogen.  This conversion takes place in the liver and muscles.

The process of breaking down glucose to convert it into glycogen is known as glycogenesis.  

Glycogens are stored in your liver and muscles for future use or as energy when there is excess food intake.  They’re also released back into the bloodstream, where they can be taken up by cells that initially need glucose or glycogen for energy.

Upon the intake of carbohydrates, the level of blood glucose rises to a point where the pancreas secretes insulin, which begins the process of breaking down glycogen into its component parts and shuttling them out into your cells to be used for cellular energy.  

Once you’re done using them, or when there’s excess glucose in the blood, insulin is again encouraged to break down glycogen and glucose for use as cellular energy or stored away in the liver.

When Does Muscle Glycogen Need To Be Replenished?

Muscle glycogen needs to be replenished within several hours after strenuous athletic competition or exercise.

This is especially important for endurance athletes who need to do another workout the next day or compete again in just a few days.

What Are Some Sources Of Muscle Glycogen?

Some foods can help you boost your muscle glycogen without having to eat excessive amounts of carbohydrates.

Many endurance runners and other athletes keep some kind of candy or nut handy to take when they finish their workouts. 

When Should You Use These Sources?

This depends on your training schedule, but you might find one that suits you best as a pre-exercise snack, during-exercise snack, or as recovery fuel.

You can even use these snacks throughout the day to help keep your muscle glycogen levels topped up.

How To Replenish Glycogen In Your Muscles

All carbohydrates are not created equal when it comes to replenishing muscle glycogen. Some sources break down quickly into glucose and fructose, while others take longer, so you need to choose your “glycogen foods” carefully.

A fast-acting carbohydrate is the best recovery fuel during exercise because it will get into your muscles quickly and help them fuel up for another bout of exercise. 

Carbohydrates break down into glucose which is the preferred energy source for the muscle fiber, but that glucose must be converted to fructose before it can be used as energy by muscles.

Once you start exercising, however, your liver takes over the processing of the fructose, which means that your muscles can’t convert it into energy. 

The trick to replenishing muscle glycogen is choosing foods that break down quickly into glucose and fructose so they will get to the muscle fibers in time for use as an immediate fuel source during exercise. This requires a carbohydrate with a high-glycemic index number (GI). 

The Glycemic Index (GI) ranks carbohydrate-containing foods according to how quickly they raise blood glucose levels. This information is useful because it helps you choose the right type of food for your recovery between workouts or competitions.

Carbohydrates are classified as low, medium, and high glycemic, depending on their GI.

Low glycemic foods have a GI score of 55 or less, which means they break down slowly into glucose and fructose for energy during exercise. Medium glycemic foods have a score between 56 and 69, while high glycemic foods score over 70.

Ways To Improve Your Diet For Better Muscle Recovery

Fiber is the component of carbohydrate-rich foods that cannot be digested, so it doesn’t break down in the stomach and intestines.

Fiber keeps your digestive system moving regularly, but only small amounts can be broken down by bacteria in your large intestine to produce gases and short-chain fatty acids, which the body uses for energy. 

Carbohydrates rich in fiber have a low glycemic score, so they can help you control your weight and replenish glycogen more slowly.

Eating foods with “resistant” starch, which is just another term for fiber, will help you keep your muscle glycogen topped up over time and make it less likely to dip into the reserves in your liver.

The most common foods that provide resistant starch are grains, beans, and legumes.

Foods that contain resistant starch are rich in dietary fiber, which is not digested or absorbed when it enters the large intestine.

Bacteria produce short-chain fatty acids from fiber to help keep you full but also provide 2 to 4 kilocalories per gram as an alternative fuel source for muscles and other organs.

If you are already eating plenty of whole grains, beans, and other high-fiber foods in your diet, there’s probably no need to add anything else.

However, if you’re not eating enough of these foods or would like a way to get more resistant starch into your daily routine, then try regularly adding food with resistant starch into your meal rotation. 

Muscle Glycogen And Keto Diet

Ketogenic diets are low in carbohydrates and high in fat, so they promote the production of ketones as an alternate energy source for the body.

This is a normal process that your body uses to go into survival mode when it does not have enough carbohydrates for energy.

Clinical studies show that low-carb diets can lead to the same level of performance as a high-carbohydrate diet, probably because they reduce the muscle glycogen stores but also increase fat metabolism.

How Cyclical Ketogenic Diets Can Help With Workouts

Cyclical ketogenic diets are low-carbohydrate, moderate protein, and high-fat for the first three phases each week with a high-carbohydrate “refeed” day in between.

The key to cyclical ketogenic diets for muscle recovery is that they support the production of ketones.

Ketones are an alternative energy source and can be burned by the muscles instead of glucose during exercise.

The brain still needs a small amount of glucose from glycogen stored in the liver, but this can provide enough energy to supply the muscles with stamina for a strong workout.

The high-carb day of a cyclical ketogenic diet allows your body to replenish muscle glycogen for energy and then move back into the normal eating plan to keep fat metabolism increased.

The high-fat meals on this type of diet help you maintain muscle mass while burning stored body fat and accelerating weight loss without feeling hungry or deprived.

The best thing about cyclical ketogenic diets is that they promote weight loss while providing plenty of energy for high-intensity workouts.

Some people are drawn towards low-carbohydrate diets because they want to lose weight and keep their muscles.

More research needs to be done about ketogenic diets for muscle recovery, but we know that high-fat foods are beneficial for muscle growth and don’t slow you down during your workouts.

Related: How To Build Muscle Mass On The Keto Diet


Muscle glycogen is an important energy storage for the body. You’ll feel sluggish and tired if your muscles are empty, as glycogen reserves in the liver can only sustain you so far.

So eat a carbohydrate-rich meal after every workout to replenish muscle glycogen stores and help muscle recovery.

Driving your body into ketosis with a cyclical ketogenic diet will provide you with an alternative energy source for the muscles that does not affect your speed or endurance during high-intensity workouts.

A ketogenic diet can be a good option if you want to lose weight while maintaining muscle mass and exercising at the same time. Eat plenty of protein to maintain muscle growth and watch out for carbohydrates while consuming healthy fats to power your workout.

Dieting does not need to be a difficult game if you know what foods promote muscle growth and which ones will slow you down during workouts.

Research the foods in your diet before making any changes so that you can decide what works best for your body and make informed decisions about what to eat.

A cyclical ketogenic diet is a popular weight-loss option for many reasons.

However, you will still be able to exercise effectively when following these plans, so enjoy all the benefits that the high-fat meals have to offer and make sure you include enough carbohydrates on your refeed days to restore muscle glycogen.

Leave a comment

Your email address will not be published.