Tw. Rowland et Ln. Cunningham, DEVELOPMENT OF VENTILATORY RESPONSES TO EXERCISE IN NORMAL WHITE-CHILDREN - A LONGITUDINAL-STUDY, Chest, 111(2), 1997, pp. 327-332
Cross-sectional studies have indicated that the pattern of ventilatory
responses to exercise evolves during the course of childhood. This 5-
year study was designed to provide a longitudinal assessment of minute
ventilation (VE), tidal volume (VT), and breathing frequency (fR) in
20 children (11 girls, nine boys) between the ages of 9 and 13 years.
Subjects performed maximal and identical submaximal steady-state tread
mill walking tests annually. No significant gender differences were ob
served in any of the three variables. At submaximal exercise, VT per k
ilogram remained stable, with a progressive fall in fR. As a result, s
ubmaximal VE per kilogram declined with age. A similar pattern was obs
erved at maximal exercise, but the decrease in VE per kilogram was not
statistically significant. Ventilatory equivalent for oxygen (VE/VO2)
fell with age at submaximal exercise but declined only in the boys wi
th maximal testing. VE/VO2 at maximal and submaximal exercise was grea
ter in the girls at all ages. These findings support previous data der
ived from cross-sectional studies.