Relationship between aerobic physical fitness and ventilatory control during exercise in young swimmers

Abstract

The aim of this study was to specify in young trained swimmers, during progressive exercise, whether different aerobic physical fitness goes along with differences in breathing pattern and in mouth occlusion pressure used as a non-invasive index of neuromuscular output. Ten children (aged 10.5–16 years) with high V̇O2max(57.6 ± 3.6 ml·min−1·kg−1) and ten children (aged 11–17 years) with moderate V̇O2max (44 ± 3.8 ml·min−1·kg−1) realized a maximal exercise test on a cycle ergometer. During the last minute of each power level we measured the following parameters: V̇O2, V̇CO2, V̇EBW, f, VυBW/T1, T1/Ttot, as well as mouth occlusion pressure (P0.1) and ‘effective impedance’ of the respiratory system (P0.1/VυBW/T1). Our results showed that at a same V̇CO2, children with high V̇O2max had significantly lower P0.1, P0.1/VυBW /T1 and f than children with moderate V̇O2max and same VeBW and VυBW/T1. At different levels of V̇CO2, in the twenty children of the two groups, we have found significant correlations between V̇O2 max of each subject and P0.1 (P<0.01), P0.1/VυBW/T1 (P<0.001). At a same V̇O2, children with a higher V̇O2max showed significantly lower P0.1, P0.1/VυBW/T1 at all levels of V̇O2 and lower VeBW and VυBW and VυBW/T1 at high level of V̇O2. At a same V̇e, the two groups of children showed the same values of Vυ/T1 and f. In conclusion this study shows first, that different aerobic physical fitness does not go along with different breathing pattern, and second, that swimmers with high physical fitness have a lower ventilatory response to exercise but a higher ventilatory and neuromuscular efficiency during exercise than children with moderate physical fitness.