title: Association between aerobic fitness and indices of autonomic regulation: cardiovascular risk implications.
abstract: BACKGROUND
  In the general population higher levels of exercise capacity seem to protect the cardiovascular system with effects well beyond traditional risk factors. We hypothesize that this phenomenon, called "risk factor gap", could be ascribed to functional components, such as autonomic adaptation to aerobic training.
  
  
  METHODS
  In 257 subjects (age 36.2±0.8 years) we measured VO2peak (incremental cycling exercise), together with arterial pressure and autonomic proxies (baroreflex gain, R-R variance and standing induced increase in marker of excitatory oscillatory regulation of the SA node, ∆LFRRnu).
  
  
  RESULTS
  Autonomic proxies appeared significantly correlated with indicators of aerobic fitness (age and gender corrected correlation between VO2peak, baroreflex gain: r=0.277, P<0.001, and DAP r=-0.228, P<0.001). Subsequently, subjects were subdivided in three age and gender adjusted categories of VO2peak (poor, medium and good). Autonomic indices and arterial pressure appeared significantly ordered with categories of VO2peak (P<0.006). In addition, within these categories the proportion of subjects with a desirable autonomic and pressure profile becomes significantly greater with better fitness levels.
  
  
  CONCLUSIONS
  The strong ordered relationship between categories of aerobic fitness and autonomic proxies speaks in favor of a complementary role of the autonomic nervous system in the management of cardiovascular risk factor gap at a population level.
authors: Department of Sports Medicine, University of Milan, Milan, Italy - daniela.lucini@unimi.it.
authors: Roberto
authors: R
authors: Sala
authors: Mara
authors: M
authors: Malacarne
authors: Massimo
authors: M
authors: Pagani
authors: Daniela
authors: D
authors: Lucini
mesh_terms: D000328:Adult; D001341:Autonomic Nervous System / Q000502:physiology*; D017704:Baroreflex; D001794:Blood Pressure; D002318:Cardiovascular Diseases / Q000209:etiology*; D015444:Exercise / Q000502:physiology; D005080:Exercise Test; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D010809:Physical Fitness / Q000502:physiology*; D011187:Posture; D012307:Risk Factors