muscle metabolism


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Related to muscle metabolism: creatinine

muscle metabolism

The consumption of energy by all cells, including those of muscle tissue, to perform work. The source of chemical energy, adenosine triphosphate (ATP), is metabolized to adenosine diphosphate (ADP). If the energy requirement is short-term, the ADP is converted back to ATP. This process is too slow to keep up with energy demands during long-term exercise; thus, consumption of other fuels is required. The main sources of fuel for muscles are carbohydrates and lipids. Before being available for intracellular metabolism, glycogen is obtained when glucose is converted to glycogen. The main lipid fuel is free fatty acids present in plasma. Carbohydrates can be metabolized either in the presence of oxygen (aerobically) or in its absence (anaerobically), but lipids can be metabolized only aerobically. During light exercise or when the body is at rest, muscle metabolism is usually entirely aerobic, and the source of fuel is the free fatty acids in plasma. During intense exercise, metabolism of the fatty acids cannot keep up with the demand, and glycogen is used for energy. However, as intense exercise continues, glycogen stores are exhausted, and free fatty acids become the principal source of energy. Trained athletes have an increased ability to metabolize fatty acids as compared with sedentary people; this permits athletes to exercise longer and at higher work rates than untrained people. Athletic trainers have found that muscle glycogen stores can be increased by carbohydrate loading.
Working articulation.
See also: metabolism
References in periodicals archive ?
Ingesting the GEL may have maintained the neurological recruitment patterns of muscle during the runs, minimized muscle metabolism disruption, or delayed the change in the frequency spectra with the onset of acute fatigue (Kroll et al.
Knowledge of the metabolic adaptations to muscle metabolism induced by repeated fasting/refeeding is limited compared with the liver (Table 1), but like the liver, a greater capacity to store and spare glycogen is suggested.
Endurance training results in skeletal muscle adaptations which may modify muscle metabolism and lead to improved aerobic exercise capacity and physical performance (1), (2), (3).
Aging also results in decreased synthesis of myofibrillar components, increased production of catabolic cytokines, atrophy, and altered muscle metabolism [18-21].
Gaitanos GC, et al: Human muscle metabolism during intermittent maximal exercise.
His PhD thesis was entitled Role of Calcium in Heart Muscle Metabolism.
A Dr Sarah Brewer says: Cramps are linked with a a build-up of lactic acid and other waste products of muscle metabolism, usually during or after physical exercise.
Another is elevated whole-body protein catabolism--a destructive form of muscle metabolism that translates to muscle wasting.
One Italian/English study on female athletes [Sports Medicine and Arthroscopy Review, March 2002] concluded that exercise helps the mother's oxygen usage, her muscle metabolism, and her glucose tolerance.
The next section (Units Three, Four and Five) examines motor function, proprioception, muscle metabolism and leverage in the context of tension as an obstruction to achieving artistic mastery.