Glycogen stores: Why they are important for sports and endurance

Glycogen is an essential source of energy for the body, especially during exercise. It is the storage form of glucose that is stored primarily in the liver and muscles. Glycogen plays a central role in energy metabolism, as it provides the body with energy quickly when needed. This article looks at the function of glycogen, the importance of glycogen stores in sport, and why they are crucial for athletes' performance.

What is glycogen?

Glycogen is a branched polysaccharide composed of glucose molecules that serves as the body's main storage form of carbohydrates. It is stored in the liver and muscles and, when needed, is converted into glucose, which is then used as an energy source for various bodily functions.

Liver glycogen:

•Liver glycogen serves primarily to maintain blood sugar levels. It is converted into glucose when needed and released into the blood to meet the energy needs of the entire body, especially the brain.

muscle glycogen:

•Muscle glycogen is stored primarily in the muscles and serves as a direct source of energy for muscle work. Unlike liver glycogen, muscle glycogen is not released into the blood but is used directly in the muscles.

The Role of Glycogen in Sports

Glycogen is especially important for sports activities that require high intensity or long duration. Here are some of the reasons why glycogen plays such a crucial role in sports:

Fast energy source:

•During intense physical activity, ATP (adenosine triphosphate), the immediate energy source of cells, is rapidly used up. Glycogen is then converted to glucose to support ATP production in muscles and maintain energy supply.

performance maintenance:

•A well-filled glycogen store allows athletes to train or compete at high intensity for long periods of time. However, when glycogen stores are depleted, performance drops significantly as the body must rely on fat burning and other less efficient energy sources.

Delaying fatigue:

•Glycogen depletion is one of the main factors leading to fatigue in endurance exercise. When glycogen stores are almost depleted, the ability of muscles to work efficiently is reduced, resulting in a significant drop in performance.

Recovery after training:

•After intense physical exertion, glycogen stores must be replenished. Rapid replenishment of glycogen stores can speed recovery and improve performance in subsequent training sessions or competitions.

Glycogen storage and sports

Different sports require different amounts of glycogen, depending on the intensity and duration of the activity:

Endurance sports:

•Marathons, long-distance cycling and triathlons require a significant amount of glycogen to maintain energy throughout the duration of the activity. Athletes in these disciplines must ensure that their glycogen stores are optimally replenished before competition and maintained during competition through carbohydrate supply.

interval training:

•Sports such as football, basketball or tennis, which combine periods of intense exertion with short recovery periods, use up muscle glycogen quickly. Restoring glycogen stores between training sessions is crucial for performance.

Strength training:

•Glycogen also plays an important role in strength training, especially with higher repetitions or longer training sessions. Well-filled glycogen stores provide the energy needed to achieve maximum performance.

Nutrition to maximize glycogen stores

Proper nutrition is crucial to replenish glycogen stores and maintain them at optimal levels. Here are some basic nutritional strategies:

Carbohydrate-rich diet:

•Carbohydrates are the primary source for replenishing glycogen stores. Athletes should ensure they consume sufficient complex carbohydrates (eg whole grains, legumes, vegetables) to maximize glycogen stores before competition or intense training sessions.

Carbohydrate loading:

•Before particularly long endurance competitions, a carbohydrate loading strategy is often used, in which carbohydrate intake is increased in the days before the competition in order to maximize glycogen stores.

Recovery nutrition:

•After intense exercise, it is important to replenish glycogen stores by consuming carbohydrates (in combination with protein). Rapid carbohydrate consumption within the first 30 minutes after exercise can maximize glycogen resynthesis.

What happens when glycogen stores are depleted?

When glycogen stores are depleted, the body can no longer provide enough energy for high-intensity activity. This can lead to a condition known in endurance sports as "bonking." Symptoms can include severe fatigue, dizziness, difficulty concentrating, and a dramatic drop in performance.

To avoid this, it is important to consume carbohydrates regularly during prolonged exercise and to ensure that glycogen stores are well filled before training or competition.

 

Glycogen is a key energy source in sport, particularly in activities that require high intensity and endurance. Proper management of glycogen stores through a high-carbohydrate diet and targeted nutritional strategies can significantly improve athletic performance. Athletes should not underestimate the importance of glycogen and ensure they are making optimal use of their glycogen stores to get the most out of their training and competition.