Abstract

In this study, we assessed the ventilatory response in 84 children (46 males: age 8.1 ± 1.0 years, body mass 34.2 ± 7.9 kg, height 1.32 ± 0.16 m; 38 females: age 8.0 ± 0.8 years, body mass 31.7 ± 8.7 kg, height 1.31 ± 0.08 m) during a cycle ergometer test to determine if there was an influence of gender on ventilatory efficiency. The test commenced at 25 W and increased by 10 W every minute. Expired air was collected through a face mask and analysed breath by breath. The ventilatory anaerobic threshold was determined according to gas exchange methods and we focused our attention on the analysis of carbon dioxide production ([Vdot]CO2), ventilation ([Vdot] E), the ratio [Vdot] E/[Vdot]CO2 and its slope. Differences between the sexes at maximal power output were strongly significant for [Vdot] E and [Vdot]CO2 (P = 0.0001 and P = 0.0004 respectively) and moderately significant for the [Vdot] E/[Vdot]CO2 ratio (P = 0.05). The slope of [Vdot] E versus [Vdot]CO2 was 30.8 ± 4.2 for males and 29.4 ± 3.2 for females, with no difference between the sexes (P = 0.1). In conclusion, although the peak values of [Vdot] E and [Vdot]CO2 were significantly different between the sexes, there were no such differences in ventilatory efficiency during a maximal incremental test expressed as the slope of [Vdot] E/[Vdot]CO2, at least in young children. Verf.-Referat