title: Central and peripheral cardiovascular adaptations during a maximal cycle exercise in boys and men.
abstract: OBJECTIVE
  Stroke volume response to exercise depends on changes in cardiac filling, intrinsic myocardial contractility, and left ventricular afterload. The purpose of this study was to compare these responses during an upright cycle test performed until exhaustion in children and adults.
  
  
  METHODS
  Stroke volume, cardiac output (Doppler echocardiography), left ventricular dimensions (two-dimensional and time-movement echocardiography), as well as arterial pressure and systemic vascular resistance (SVR) were assessed in 17 boys (mean age, 11.7 +/- 0.6 yr) and 23 young adult men (mean age, 21.2 +/- 2.7 yr) having a similar aerobic potential. All variables were measured at the end of the resting period, during the final minute of each workload, and during the last minute of the test.
  
  
  RESULTS
  No significant differences were obtained for stroke volume, cardiac output, and left ventricular dimensions when they were scaled to body surface area at rest and whatever the exercise intensity. However, arteriovenous oxygen uptake was higher and the SVR lower in the adults than in the children.
  
  
  CONCLUSIONS
  The patterns of stroke volume, as well as its underlying mechanisms, were not age-related during an upright maximal exercise test. However, other studies are required to understand further the effect of pubertal status on the peripheral cardiovascular system.
authors.affiliation: Laboratoire de Physiologie des Adaptations Cardiovasculaires à L'Exercice, Faculté des Sciences, Département STAPS, 84000 Avignon, France. stephane.nottin@libertysurf.fr
authors.forename: Stéphane
authors.initials: S
authors.lastname: Nottin
authors.forename: Agnès
authors.initials: A
authors.lastname: Vinet
authors.forename: François
authors.initials: F
authors.lastname: Stecken
authors.forename: Long-Dang
authors.initials: LD
authors.lastname: Nguyen
authors.forename: Fawsi
authors.initials: F
authors.lastname: Ounissi
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Lecoq
authors.forename: Philippe
authors.initials: P
authors.lastname: Obert
mesh_terms: D000222:Adaptation, Physiological; D000328:Adult; D002648:Child; D015150:Echocardiography, Doppler; D015444:Exercise / Q000502:physiology*; D006339:Heart Rate; D006801:Humans; D008297:Male; D009200:Myocardial Contraction; D010101:Oxygen Consumption; D011659:Pulmonary Gas Exchange; D013318:Stroke Volume; D016277:Ventricular Function, Left