Central and peripheral cardiovascular adaptations during a maximal cycle exercise in boys and men.
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.
Nottin
Stéphane
S
Laboratoire de Physiologie des Adaptations Cardiovasculaires à L'Exercice, Faculté des Sciences, Département STAPS, 84000 Avignon, France. stephane.nottin@libertysurf.fr
Vinet
Agnès
A
Stecken
François
F
Nguyen
Long-Dang
LD
Ounissi
Fawsi
F
Lecoq
Anne-Marie
AM
Obert
Philippe
P
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