Table 1.
Descriptive statistics (mean ± SD) of the players grouped by age category.
| Variable | U10 N = 26 |
U11 N = 26 |
U12 N = 26 |
U13 N = 41 |
U14 N = 31 |
U15 N = 28 |
U16 N = 29 |
U19 N = 35 |
|---|---|---|---|---|---|---|---|---|
| Age (y) | 9.9 ± 0.2 | 10.8 ± 0.3 | 11.7 ± 0.3 | 12.8 ± 0.3 | 13.9 ± 0.2 | 14.9 ± 0.2 | 15.5 ± 0.5 | 17.7 ± 0.5 |
| Weight (kg) | 31.6 ± 4.0 | 31.6 ± 4.6 | 35.9 ± 5.2 | 39.7 ± 7.4 | 48.0 ± 7.5 | 55.4 ± 5.8 | 63.8 ± 7.1 | 67.7 ± 6.0 |
| Height (cm) | 131.6 ± 6.2 | 144.5 ± 5.3 | 151.1 ± 7.5 | 152.8 ± 11.1 | 167.7 ± 8.0 | 174.0 ± 7.2 | 176.1 ± 5.9 | 177.4 ± 5.8 |
| BMI (kg/m2) | 16.9 ± 1.4 | 17.1 ± 1.5 | 18.7 ± 1.7 | 19.3 ± 2.1 | 20.7 ± 1.9 | 21.1 ± 1.0 | 21.8 ± 1.8 | 22.0 ± 1.3 |
| Sitting height (cm) | 61.1 ± 2.9 | 71.5 ± 2.9 | 73.3 ± 3.9 | 77.9 ± 3.5 | 83.7 ± 4.1 | 88.3 ± 3.5 | 93.2 ± 2.5 | 88.9 ± 3.6 |
| Leg length (cm) | 70.5 ± 5.0 | 73.0 ± 4.0 | 77.8 ± 13.8 | 74.9 ± 10.6 | 84.0 ± 4.5 | 85.7 ± 4.7 | 82.9 ± 4.5 | 88.5 ± 5.6 |
| YPHV (y) | −3.8 ± 0.3 | −3.0 ± 0.3 | −2.4 ± 0.5 | −1.3 ± 0.5 | −0.1 ± 0.6 | 1.0 ± 0.5 | 2.0 ± 0.5 | 2.5 ± 0.5 |
| FM (%) | 12.8 ± 2.2 | 14.0 ± 3.2 | 15.9 ± 3.9 | 13.9 ± 4.0 | 12.3 ± 3.0 | 10.9 ± 1.9 | 13.3 ± 2.5 | 14.7 ± 2.5 |
| FFM (kg) | 27.6 ± 3.1 | 30.8 ± 3.5 | 33.3 ± 4.0 | 41.3 ± 5.9 | 48.5 ± 6.4 | 58.0 ± 5.8 | 58.7 ± 5.8 | 59.0 ± 4.2 |
| UMA (cm2) | 20.6 ± 3.5 | 24.6 ± 4.7 | 25.7 ± 5.0 | 29.3 ± 5.6 | 36.3 ± 6.1 | 45.8 ± 4.7 | 45.9 ± 7.5 | 44.3 ± 6.4 |
| UFA (cm2) | 7.6 ± 1.8 | 8.6 ± 2.5 | 9.8 ± 2.8 | 8.8 ± 3.3 | 8.5 ± 2.8 | 7.8 ± 1.9 | 11.1 ± 2.9 | 11.5 ± 3.5 |
| CMA (cm2) | 44.8 ± 5.4 | 48.0 ± 8.6 | 54.2 ± 19.1 | 60.8 ± 9.3 | 69.1 ± 13.4 | 65.7 ± 6.9 | 81.6 ± 12.6 | 74.6 ± 11.2 |
| CFA (cm2) | 18.5 ± 5.7 | 20.5 ± 6.6 | 24.8 ± 7.1 | 23.2 ± 7.5 | 22.9 ± 7.1 | 19.6 ± 3.4 | 24.4 ± 5.9 | 27.1 ± 5.6 |
| TMA (cm2) | 99.7 ± 12.5 | 109.8 ± 13.5 | 119.9 ± 25.7 | 132.9 ± 21.8 | 156.6 ± 27.9 | 183.7 ± 14.2 | 183.5 ± 22.2 | 195.4 ± 20.8 |
| TFA (cm2) | 19.4 ± 4.3 | 22.3 ± 6.3 | 23.8 ± 8.8 | 23.1 ± 7.7 | 22.6 ± 6.1 | 21.3 ± 4.2 | 24.5 ± 7.2 | 27.7 ± 9.0 |
| R/H (ohm/m) | 465.4 ± 53.0 | 440.8 ± 42.7 | 416.2 ± 57.4 | 392.9 ± 55.9 | 313.5 ± 39.7 | 276.0 ± 19.4 | 265.4 ± 17.6 | 249.7 ± 20.2 |
| Xc/H (ohm/m) | 48.3 ± 5.7 | 46.8 ± 5.6 | 44.7 ± 6.9 | 40.1 ± 5.3 | 37.1 ± 3.9 | 33.8 ± 3.0 | 34.1 ± 3.1 | 34.0 ± 3.8 |
| PA (°) | 6.0 ± 0.6 | 6.1 ± 0.5 | 6.2 ± 0.5 | 5.9 ± 0.5 | 6.8 ± 0.8 | 7.0 ± 0.5 | 7.4 ± 0.6 | 7.8 ± 0.6 |
| VL/H (ohm/m) | 467.9 ± 53.1 | 443.3 ± 42.9 | 418.6 ± 57.7 | 395.0 ± 56.1 | 315.7 ± 39.7 | 278.1 ± 19.5 | 267.6 ± 17.6 | 252.0 ± 20.4 |
| TBW (l) | 20.9 ± 2.1 | 22.9 ± 3.2 | 25.1 ± 4.1 | 30.9 ± 3.0 | 35.5 ± 3.6 | 42.4 ± 3.6 | 43.0 ± 2.7 | 42.8 ± 3.2 |
| BCM (kg) | 21.9 ± 1.4 | 22.4 ± 1.8 | 23.5 ± 1.8 | 23.9 ± 2.2 | 28.7 ± 4.1 | 31.7 ± 2.0 | 33.4 ± 2.0 | 35.7 ± 2.4 |
Note: BMI = body mass index; YPHV = years from peak high velocity; FM = fat mass; FFM = fat free mass; UMA = upper arm muscle area; UFA = upper arm fat area; CMA = calf muscle area; CFA = calf fat area; TMA = thigh muscle area; TFA = thigh fat area, R/H = resistance standardized for height, Xc/H = reactance standardized for height, PA = phase angle, VL/H = vector length standardized for height, TBW = total body water, BCM = body cell mass.