Bioenergetic provision of energy for muscular activity

A complex series of metabolic pathways are present in human muscle that break down substrates from nutritional sources to produce energy for different types of muscular activity. However, depending on the activity in which an individual is engaged, the body will make use of different energy systems that have been adapted for the particular activity. More specifically, utilization of bioenergetic substrates depends on the type, intensity, and duration of the exercise. The aerobic oxidative system is used for longer duration activities of low to moderate intensity, the anaerobic glycolytic system is used for short to moderate duration activities of higher intensity, and the high energy phosphagen system is used for short duration activities of high intensity. The efficiency and effectiveness of these pathways can be enhanced through physical activity and training. It is these bioenergetic pathways that are the focus of this review.