[Effects of physical exercise on the cardiorespiratory system in children]

Our aim was to perform a prospective study to evaluate the effects of competitive sports on the cardiorespiratory system and physical performance in children.

Male children aged 6 and 7 years were selected from a public school (PS) and from a soccer sports school (SS). They underwent anthropometrical measurement. Those boys who were further than one standard deviation from the 50th percentile were excluded from the study. A total of 74 boys were selected with 41 being from the PS and 33 from the SS. Three different physical competitive activities were performed by the children. Hemodynamic measurements [heart rate (HR), systolic, mean and diastolic blood pressure (SBP, MBP and DBP)] and respiratory measurements [respiratory rate (RR), arterial oxygen saturation (SatO2), peak expiratory flow (PEF), forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and the FEV1/FVC relationship] were taken before and after the physical activity.

Overall we found a significantly higher physical performance in the SS group (p < 0.001). The HR before and after exercise was significantly lower in the SS group. The comparison between constants before and after physical activity in each group showed a significant increase in HR, SBP, MBP and DBP in the PS group, but there was no difference between the SBP before and after physical activity in the SS group. The SS group had a significantly lower RR and better SatO2 in the basal measurement. The relationship between constants before and after physical activity showed a rise in the PEF in the PS group and a decrease in the SatO2 in the SS group.

We recommend controlled physical competitive activity in children because of its benefits on cardiorespiratory function and the absence of adverse effects.