Ventilatory response to exercise and rating of perceived exertion in two pediatric age groups

The aim of this paper is to study the differences in ventilatory response to exercise in prepubertal and pubertal children. One hundred children in the following groups: 10-year-olds (25 boys/25 girls) and 13-year-olds (25 boys/25 girls) performed sub maximal treadmill stress test, using modified Balke protocol. All of them went through complex pulmonary function testing and complete anthropometrics measurements, including skinfold thickness. The relative oxygen consumption for the whole group is 38.5 +/- 4.5 mL/min/kg (mean +/- SD). The girls had higher percent fat than boys in both groups (24% vs. 16% in the first group and 27% vs. 18% in the second). With age VO2peak grows parallel with minute ventilation, tidal volume and a tendency towards lowering the breathing frequency is observed irrespective of the sex. We found significant sex differences in ventilatory equivalents for oxygen and carbon dioxide in the second group. VE/VCO2 for the boys decreased from 30.6 +/- 3.1 to 27.6 +/- 2.9; p = 0.002, but remains unchanged in girls. Another interesting fact is that older children rated perceived exertion significantly higher (Borg score 4.6 +/- 0.9 vs. 5.5 +/- 1.4; p < 0.05) despite the standard load. In conclusion there are age and sex differences in some aspects of ventilatory response in pediatric age group.