[Cardiorespiratory responses during progressive maximal exercise test in healthy children].
BACKGROUND
Little is known about cardiorespiratory and metabolic response in healthy children during progressive maximal exercise test.


OBJECTIVE
To test the hypothesis that children show different responses in cardiorespiratory and metabolic parameters during progressive maximal exercise test when compared with adults.


METHODS
Twenty-five healthy children (gender, 15M/10F; age, 10.2 +/- 0.2) and 20 healthy adults (gender, 11M/9F; age, 27.5 +/- 0.4) underwent a progressive treadmill cardiopulmonary test until exhaustion to determine the maximal aerobic capacity and ventilatory anaerobic threshold (VAT).


RESULTS
The peak workload (5.9+/-0.1 vs 5.6+/-0.1 mph, respectively; p>0.05), exercise time (9.8+/-0.4 vs 10.2+/-0.4 min, respectively; p>0.05), and relative aerobic fitness (VO(2)peak, 39.4+/-2.1 vs 39.1+/-2.0 ml*kg(-1)*min-1, respectively; p>0.05) were similar in children and adults. At ventilatory anaerobic threshold, the heart rate, VO(2) ml*kg(-1)*min-1, respiratory rate (RR), functional estimate of dead space (VD/VT), ventilatory equivalent for oxygen (VE/VO(2)) and end-tidal pressure for oxygen (PETO2) were higher in children, while tidal volume (VT), O(2) pulse and end-tidal pressure for carbon dioxide (PETCO(2)) were lower. At peak of exercise, children showed higher RR and VD/VT. However, O(2) pulse, VT, pulmonary ventilation, PETCO(2) and respiratory exchange ratio were lower in children than adults.


CONCLUSIONS
Cardiorespiratory and metabolic responses during progressive exercise test are different in children as compared to adults. Specifically, these differences suggest that children have lower cardiovascular and ventilatory efficiency. However, children showed higher metabolic efficiency during exercise. In summary, despite the differences observed, children showed similar levels of exercising capacity when compared with adults.
Prado
Danilo Marcelo Leite do
DM
Instituto do Coração, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP - Brazil. danilomprado@usp.br
Braga
Ana Maria F Wanderley
AM
Rondon
Maria Urbana Pinto
MU
Azevedo
Luciene Ferreira
LF
Matos
Luciana D N J
LD
Negrão
Carlos Eduardo
CE
Trombetta
Ivani Credidio
IC
D000328:Adult; D000367:Age Factors; D000704:Analysis of Variance; D016009:Chi-Square Distribution; D002648:Child; D005080:Exercise Test / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology*; D005082:Physical Exertion / Q000502:physiology*; D012123:Pulmonary Ventilation / Q000502:physiology*