Table 3.
Biological maturity, anthropometric characteristics and ranking positions of youth elite tennis players according to birth distribution.
| Age Group | 1st Q | 2nd Q | 3rd Q | 4th Q | P | Post hoc | ES ± (90%CI) | |
|---|---|---|---|---|---|---|---|---|
| APHV [year] | U12 | 13.8 ± 0.5 | 13.8 ± 0.3 | 13.4 ± 0.4 | 13.2 ± 0.5 | .001 | Q1>Q3;Q4 Q2>Q4 | 1.28 (-.25; .97) |
| U13 | 14.2 ± 0.6 | 13.8 ± 0.5 | 13.9 ± 0.5 | 13.7 ± 0.3 | .358 | n.d | .36 (-0.48; 1.41) | |
| U14 | 13.7 ± 0.8 | 13.8 ± 0.6 | 13.8 ± 0.6 | 14.1 ± 0.5 | .532 | n.d. | .56 (-0.95; 0.11) | |
| U15 | 13.8 ± 0.6 | 13.9 ± 0.6 | 14.0 ± 0.8 | 13.8 ± 0.7 | .843 | n.d. | .06 (-0.29; 0.39) | |
| U16 | 13.8 ± 0.5 | 13.8 ± 0.7 | 13.4 ± 0.3 | 13.3 ± 0.6 | .170 | n.d. | .70 (-0.07; 0.77) | |
| U17 | 14.0 ± 0.6 | 13.9 ± 0.5 | 13.9 ± 0.6 | 13.5 ± 0.4 | .576 | n.d. | .74 (-0.14; 1.08) | |
| Years from/to APHV [year] | U12 | -2.07 ± 0.5 | -2.3 ± 0.3 | -2.2 ± 0.4 | -2.2 ± 0.5 | .294 | n.d. | .31 (-0.21; 0.51) |
| U13 | -1.7 ± 1.7 | -1.4 ± 0.5 | -1.7 ± 0.5 | -1.8± 0.3 | .731 | n.d. | .05 (-0.64; 1.18) | |
| U14 | 0.0 ± 0.8 | -0.3 ± 0.6 | -0.5 ± 0.6 | -1.1 ± 0.4 | .001 | Q1;Q2>Q4 | 1.58 (0.72; 1.75) | |
| U15 | 0.9 ± 0.6 | 0.5 ± 0.7 | 0.1 ± 0.9 | 0.2 ± 0.6 | .013 | Q1>Q3;Q4 | 1.06 (0.30; 1.10) | |
| U16 | 2.0 ± 0.5 | 1.7 ± 0.7 | 1.8 ± 0.3 | 1.6 ± 0.6 | .619 | n.d. | .60 (-0.12; 0.82) | |
| U17 | 2.8 ± 0.6 | 2.6 ± 0.5 | 2.3 ± 0.6 | 2.4 ± 0.5 | .334 | n.d. | .53 (-0.42; 0.82) | |
| Height [cm] | U12 | 151.0 ± 7.5 | 148.0 ± 5.4 | 150.0 ± 8.0 | 151.2 ± 9.7 | .641 | n.d. | .03 (-6.25; 5.77) |
| U13 | 157.3 ± 8.1 | 157.1 ± 8.6 | 155.6 ± 6.4 | 154.0 ± 4.7 | .604 | n.d. | .40 (-1.17: 7.78) | |
| U14 | 167.7 ± 7.5 | 165.5 ± 6.5 | 164.4 ± 8.1 | 157.5 ± 7.7 | .024 | Q1>Q4 | 1.31 (4.55; 15.79) | |
| U15 | 174.7 ± 6.5 | 170.4 ± 8.2 | 167.2 ± 10.0 | 168.8 ± 7.0 | .044 | n.d. | .88 (1.84; 10.13) | |
| U16 | 178.2 ± 5.4 | 179.3 ± 8.7 | 179.6 ± 4.9 | 180.5 ± 6.1 | .898 | n.d. | .39 (-7.32; 2.56) | |
| U17 | 181.2 ± 4.9 | 180.6 ± 3.8 | 178.4 ± 6.2 | 180.0 ± 6.3 | .677 | n.d. | .22 (-4.09; 6.51) | |
| Body mass [kg] | U12 | 39.5 ± 5.9 | 36.3 ± 3.0 | 39.8 ± 6.3 | 40.8 ± 5.6 | .192 | n.d. | .22 (-5.77; 3.15) |
| U13 | 45.5 ± 6.9 | 43.9 ± 8.7 | 41.3 ± 4.9 | 40.2 ± 3.6 | .067 | n.d. | .73 (1.50; 9.09) | |
| U14 | 54.0 ± 8.8 | 50.8 ± 6.4 | 49.9 ± 8.4 | 42.2 ± 4.6 | .009 | Q1>Q4 | 1.43 (5.82; 17.80) | |
| U15 | 61.2 ± 8.5 | 57.5 ± 9.4 | 55.0 ± 11.2 | 56.7 ± 8.2 | .292 | n.d. | .52 (-0.75; 9.63) | |
| U16 | 65.7 ± 5.5 | 64.9 ± 8.0 | 69.7 ± 4.1 | 67.5 ± 9.7 | .565 | n.d. | .22 (-8.16; 4.68) | |
| U17 | 73.0 ± 6.3 | 67.9 ± 4.8 | 71.4 ± 7.0 | 72.4 ± 9.1 | .243 | n.d. | .09 (-6.43; 7.73) | |
| Ranking [national U18] | U12 | 1838.0 ± 742.7 | 1918.0 ± 889.8 | 2255.4 ± 917.1 | 1445.0 ± 932.1 | .177 | n.d. | .49 (-197.8; 983.9) |
| U13 | 981.5 ± 463.3 | 1132.8 ± 557.3 | 1195.8 ± 751.7 | 891.0 ± 286.6 | .341 | n.d. | .16 (-167.5; 348.5) | |
| U14 | 726.1 ± 514.5 | 833.4 ± 927.8 | 887.0 ± 968.3 | 646.3 ± 317.7 | .888 | n.d. | .16 (-274.8; 434.4) | |
| U15 | 325.7 ± 240.0 | 405.6 ± 542.5 | 367.2 ± 157.3 | 455.7 ± 460.7 | .799 | n.d. | .38 (-339.5; 79.6) | |
| U16 | 120.2 ± 69.3 | 153.6 ± 112.3 | 360.1 ± 338.9 | 201.6 ± 206.6 | .104 | n.d. | .55 (-203.4; 40.7) | |
| U17 | 72.8 ± 91.1 | 192.6 ± 372.7 | 152.0 ± 163.6 | 102.5 ± 134.6 | .664 | n.d. | .28 (-133.4; 74.0) |
APHV: estimated age from/to peak height velocity; U12-U17: under 12 to under 17: Q1-Q4: first quarter to fourth quarter; ES: effect size; 90%CI: 90% confidence intervals