Exercise physiology refers to the reactions and adaptations of the human body to physical activity. It analyzes how the cardiovascular respiratory energy and muscular systems react and adjust to optimize performance improve health and manage fatigue. This abundantly illustrated reference work on sports physiology describes the three energy systems involved in physical effort: anaerobic alactic anaerobic lactic and aerobic. It explains the energy substrates reactions functioning and limiting factors of each pathway. The concepts of VO2 max threshold O2 debt and energy adaptation are also covered.