Muskelager

Muskelager is a term used in physiology to describe the energy and substrate stores located in skeletal muscle tissue. The main components are glycogen, intramuscular triglycerides (IMTG), and high-energy phosphate compounds such as phosphocreatine. These stores support muscle contraction by providing glucose for glycolysis, fatty acids for oxidation, and immediate ATP during short bursts of activity.

Muscle glycogen serves as a major local energy reserve. It is synthesized from glucose and stored in muscle fibers, where its breakdown supplies glucose-6-phosphate for glycolysis during contraction. Unlike liver glycogen, muscle glycogen cannot be released into the bloodstream to raise blood glucose.

Intramuscular triglycerides provide another energy source, particularly during longer aerobic work. The contribution of IMTG depends on training, diet, and hormonal state. Phosphocreatine acts as a rapid energy buffer, rapidly donating phosphate to resynthesize ATP in the first seconds of intense effort; it is then replenished during rest.

Repletion of muskelager after exercise primarily occurs through carbohydrate intake to rebuild glycogen, with adequate protein supporting tissue repair. Regular training and sufficient rest can increase muscle stores over time. The size and composition of muskelager vary with fitness level, diet, age, and metabolic health.

The concept of muskelager is relevant for understanding athletic performance, recovery, and metabolic health. Direct measurement of these stores is typically limited to research settings and may require invasive procedures or specialized imaging.