Table 1 Main anthropometric and CPET data
Parameters | Variables | All | Girls | Boys | P-value* |
|---|---|---|---|---|---|
| Â | N | 909 | 432 | 477 | Â |
Anthropometry | Age (years) | 11.4 ± 2.7 | 11.5 ± 2.7 | 11.2 ± 2.6 | 0.06 |
|  | Height (cm) | 151.2 ± 15.5 | 151.2 ± 14.2 | 151.3 ± 16.6 | 0.90 |
|  | Weight (Kg) | 47.9 ± 21.1 | 48.3 ± 19.8 | 47.5 ± 22.3 | 0.57 |
|  | BMI (Kg/m2) | 20.3 ± 6.2 | 20.6 ± 6.2 | 20.0 ± 6.2 | 0.13 |
|  | BMI (percentile) | 56.6 ± 30.8 | 57.9 ± 30.3 | 55.4 ± 31.2 | 0.22 |
|  | BMI ≥ 85th percentile (n) | 232 | 116 | 116 | 0.42 |
|  | Sex ratio (male/female) | 1.1 | – | – |  |
Spirometry | FEV1 (Z-score) | 0.02 ± 1.16 | − 0.10 ± 1.06 | 0.12 ± 1.22 | < 0.01 |
|  | FVC (Z-score) | 0.08 ± 1.27 | 0.01 ± 1.16 | 0.14 ± 1.37 | 0.14 |
|  | FEV1/FVC (Z-score) | − 0.06 ± 1.15 | − 0.18 ± 1.10 | 0.04 ± 1.18 | 0.01 |
Maximal parameters | VO2max (mL/min) | 1794 ± 556 | 1639 ± 427 | 1934 ± 620 | < 0.01 |
|  | VO2max (mL/Kg/min) | 40.0 ± 9.4 | 36.1 ± 7.9 | 43.5 ± 9.3 | < 0.01 |
|  | HRmax (bpm) | 188.1 ± 8.9 | 188.1 ± 8.9 | 188.2 ± 8.8 | 0.84 |
|  | RERmax | 1.15 ± 0.11 | 1.16 ± 0.12 | 1.14 ± 0.10 | < 0.01 |
|  | Maximum workload (Watts) | 141 ± 50 | 129 ± 38 | 153 ± 56 | < 0.01 |
|  | O2 pulsemax (mL) | 9.6 ± 3.0 | 8.7 ± 2.4 | 10.3 ± 3.3 | < 0.01 |
Submaximal parameters | VAT (mL/min) | 1254 ± 386 | 1148 ± 315 | 1350 ± 419 | < 0.01 |
|  | VAT (mL/Kg/min) | 28.1 ± 7.2 | 25.4 ± 6.3 | 30.5 ± 7.1 | < 0.01 |
|  | %-Predicted VAT (%) | 70.4 ± 9.0 | 70.4 ± 9.5 | 70.4 ± 8.5 | 0.97 |
|  | VE/VCO2 slope | 30.4 ± 4.3 | 30.6 ± 4.5 | 30.1 ± 4.2 | 0.1 |
|  | OUES | 1943 ± 636 | 1776 ± 526 | 2086 ± 685 | < 0.01 |
|  | OUESkg | 42.4 ± 11.4 | 38.0 ± 9.7 | 46.1 ± 11.4 | < 0.01 |
Ventilatory parameters | VTmax (L) | 1.34 ± 0.48 | 1.28 ± 0.42 | 1.40 ± 0.53 | < 0.01 |
|  | VTmax (mL/Kg) | 29.4 ± 7.1 | 27.8 ± 6.5 | 30.9 ± 7.3 | < 0.01 |
|  | RRmax (/min) | 50.2 ± 10.0 | 49.2 ± 9.8 | 51.1 ± 10.2 | < 0.01 |
|  | Breathing reserve (%) | 26.4 ± 14.7 | 28.7 ± 15.5 | 24.3 ± 13.7 | < 0.01 |
|  | VEqCO2max | 30.8 ± 3.7 | 31.0 ± 3.8 | 30.6 ± 3.6 | 0.12 |
|  | VEqO2max | 35.5 ± 5.6 | 36.2 ± 5.8 | 35.0 ± 5.3 | < 0.01 |