Exercise testing in children: Comparison in ventilatory thresholds changes with interval‐training

The aim of this investigation was, first, to examine comparatively the changes in first and second ventilatory thresholds (VT1 and VT2) and, secondly, to compare with peak oxygen uptake ({ {V}} ₎{ ₂ peak}) changes following high-intensity interval training (HIT) in prepubescent children. Eighteen prepubescent children (aged 10. 1 ± 0. 7 years) performed an incremental exhaustive exercise on a cycle ergometer with pulmonary gas exchange measurements before and after an 8-week period. During this period, nine children (five girls and four boys; initial { {V}} ₎{ ₂ peak}: 39. 6 ± 6. 0 ml O2 · min (-1) · kg (-1) ) took part in a HIT and nine other children (three girls and six boys; initial { {V}} ₎{ ₂ peak}: 39. 8 ± 7. 8 ml O2 · min (-1) · kg (-1) ), considered as controls, were not trained. After the training period, VT1, VT2, and { {V}} ₎{ ₂ peak} were significantly (P < 0. 01) improved (21%, 24%, and 14%, respectively) without significant changes in the control group. However, the changes in VT1 (ΔVT1 = +4. 35 ± 4. 36 ml O2 · min (-1) · kg (-1) ), VT2 (ΔVT1 = +7. 17 ± 5. 17 ml O2 · min (-1) · kg (-1) ), { {V}} ₎{ ₂ peak} ({ {V}} ₎{ ₂ peak} = +5. 51 ± 4. 17 ml O2 · min (-1) · kg (-1) ) induced by HIT in trained children were not related. In conclusion, for prepubescent children, in addition to VT1 and { {V}} ₎{ ₂ peak}, VT2 can also be significantly improved by training. Therefore, HIT represents a good way to obtain great improvement in these parameters in only 8 weeks. However, the time courses of these aerobic fitness parameters are dissociated, which implies the need to differentiate among them during aerobic fitness exercise testing.