How much glycogen is stored in the body

During low-intensity activities, however, you burn mostly fat and little glycogen carbs. As you ride harder, your body switches over mostly to glycogen and less fat. About 80 percent of that is stored in your muscles; the rest is stashed away in your liver. You burn about one gram per minute just riding along; about two grams per minute at endurance pace, and three grams per minute at race pace. So most people will start to tap out their glycogen supply after 90 to minutes.

Repeated high-intensity efforts can drain your stores more rapidly. You bonk. That means slowing way down. You may feel weak; your legs seem heavy; and sometimes your brain can get foggy. That amount, of course, is based on your body composition and how active you are. Use these recommendations on exercise level and daily carb intake and as your guide. Each gram of carbohydrate provides four calories of energy. Additionally, any amount of weight loss can have the same effect on glycogen stores.

Initially, you may experience a rapid drop in weight. After a period of time, your weight may plateau and possibly even increase. The phenomenon is partly due to the composition of glycogen, which is primarily water. In fact, the water in these molecules accounts for three to four times the weight of the glucose itself. As such, rapid depletion of glycogen at the onset of the diet triggers the loss of water weight. Over time, glycogen stores are renewed and the water weight begins to return.

When this happens, weight loss may stall or plateau. Gains experienced in the beginning come from water loss, not fat loss, and are only temporary. Fat loss can continue despite the short-term plateau effect.

The body can store around 2, calories of glucose as glycogen. For endurance athletes who burn that many calories in a couple of hours, the amount of stored glucose can be an impediment. When these athletes run out of glycogen, their performance almost immediately begins to suffer—a state commonly described as "hitting the wall.

If you're undertaking a strenuous exercise routine, there are several strategies endurance athletes use to avoid decreased performance you may find helpful:.

Get exercise tips to make your workouts less work and more fun. Low-carbohydrate weight-loss diets. Effects on cognition and mood. Glycogen metabolism in humans. BBA Clinical. The effects of a ketogenic diet on exercise metabolism and physical performance in off-road cyclists. Your Privacy Rights. To change or withdraw your consent choices for VerywellFit. At any time, you can update your settings through the "EU Privacy" link at the bottom of any page.

These choices will be signaled globally to our partners and will not affect browsing data. That is because glycogen is a chain of glucose molecules, that has multiple places to start the breakdown.

Also, glycogen is already located in the muscle. The breakdown of glucose however, costs a little bit of energy. It needs to be transported from the blood into the muscle. Contrary to fat combustion, carbohydrate combustion increases exponentially with intensity. The faster you swim, run, ski, bike, … the more carbohydrates you burn.

The exact amount of carbohydrates that an athlete burns at a certain intensity, depends among others on his metabolic profile. INSCYD does not only accurately provide you those metabolic parameters, it also shows you exactly how much fat and carbohydrates you burn at any intensity e. Learn more about fat and carbohydrate utilization via this blog. The carbohydrates that will be combusted come from two sources: carbohydrate stored in the muscle glycogen and carbohydrates located in the blood, as a result of carbohydrate food intake blood glucose.

In conclusion: the higher the intensity the more glycogen is needed. By consuming additional carbohydrates during exercise, you can decrease the amount of glycogen needed. However, since glycogen is preferred over blood glucose as a fuel, and because the amount of exogenous carbohydrate intake is limited, you can never exercise at a high intensity and not burn any glycogen. We know glycogen storage can be depleted rapidly. We also know this will cause fatigue to develop quickly.

But how long does it take before glycogen stores are empty? To give you a rule of thumb: after approximately 80 minutes of exercise at a maximum lactate steady state, glycogen stores are depleted. Although this rule of thumb gives you an idea, a ballpark number, it does not help the individual athlete to train and perform better.

It takes into account all the variables that affect glycogen availability and lets you know exactly how much glycogen is stored in your active muscles. Combine this knowledge with the carbohydrate combustion rate we showed in the previous graph, and you know how long glycogen stores will last. Of course you can extent the time glycogen stores last. Read along to learn how to maintain glycogen stores during exercise. Knowing the importance of glycogen, it should come as no surprise that running out of glycogen will seriously hamper exercise performance.

As the carbohydrate combustion graph clarifies, it is impossible to exercise at higher intensities when there are no carbohydrates available. In short: running out of glycogen is the end of every high performance effort. That is why you want to know exactly how much glycogen is available in an individual athlete, instead of having some rough estimates. Now you know the disastrous effects of running out of glycogen, you probably wonder how you can maintain glycogen stores during exercise.

The most obvious one is to decrease exercise intensity. This will decrease carbohydrate combustion, increase fat combustion, and as a result: maintain glycogen stores for a longer period of time. Examples are energy drinks, bars and gels. Long-term, you can also maintain glycogen stores longer by increasing fitness level. As mentioned, a higher fitness level will increase the maximal amount of glycogen stored per kilo muscle mass. When an increase in fitness level comes from an increase in aerobic power, you will also rely less on carb combustion and more on fat combustion.

By playing around with the INSCYD glycogen availability calculator, you can see how changes in fitness level and aerobic power have an effect on how long an individual can maintain glycogen stores during exercise. Experiencing low glycogen stores is of course not a big problem once you crossed the finish line. In fact, in most races or intense training sessions, this is inevitable.