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