Principles of exercise physiology: responses to acute exercise and long-term adaptations to training

PM R. 2012 Nov;4(11):797-804. doi: 10.1016/j.pmrj.2012.10.007.


Physical activity and fitness are associated with a lower prevalence of chronic diseases, such as heart disease, cancer, high blood pressure, and diabetes. This review discusses the body's response to an acute bout of exercise and long-term physiological adaptations to exercise training with an emphasis on endurance exercise. An overview is provided of skeletal muscle actions, muscle fiber types, and the major metabolic pathways involved in energy production. The importance of adequate fluid intake during exercise sessions to prevent impairments induced by dehydration on endurance exercise, muscular power, and strength is discussed. Physiological adaptations that result from regular exercise training such as increases in cardiorespiratory capacity and strength are mentioned. The review emphasizes the cardiovascular and metabolic adaptations that lead to improvements in maximal oxygen capacity.

Publication types

  • Review

MeSH terms

  • Adaptation, Physiological*
  • Adenosine Triphosphate / metabolism
  • Age Factors
  • Blood Pressure / physiology
  • Cardiac Output / physiology
  • Dehydration / physiopathology
  • Energy Metabolism / physiology
  • Exercise / physiology*
  • Glycolysis / physiology
  • Heart Rate / physiology
  • Humans
  • Lactic Acid / metabolism
  • Mitochondria, Muscle / physiology
  • Muscle Contraction / physiology
  • Muscle Fibers, Skeletal / physiology
  • Muscle, Skeletal / physiology
  • Oxidative Phosphorylation
  • Oxygen Consumption / genetics
  • Oxygen Consumption / physiology
  • Phosphocreatine / metabolism
  • Physical Education and Training
  • Physical Endurance / physiology
  • Physical Fitness / physiology
  • Plasma Volume / physiology
  • Practice Guidelines as Topic
  • Sex Factors


  • Phosphocreatine
  • Lactic Acid
  • Adenosine Triphosphate