Table 2 Maturity-related differences in anthropometry, body composition and maximal voluntary joint torque in adolescent boys

Age, years

13.0 ± 0.4

13.3 ± 0.6

13.7 ± 0.6

14.0 ± 0.6

14.1 ± 0.6

1 < 3 to 5, 2 < 4-5

0.19

Height, cm

146.6 ± 8.1

154.6 ± 7.7

159.7 ± 7.1

165.1 ± 5.8

165.4 ± 5.3

1 < 2 to 5, 2 < 4 to 5, 3 < 4

0.20

Weight, kg

38.8 ± 6.4

43.2 ± 8.2

47.4 ± 7.0

53.7 ± 5.6

53.4 ± 7.7

1 < 3 to 5, 2 < 4 to 5, 3 < 4

0.13

BMI, kg/m ²

18.0 ± 1.6

18.0 ± 1.9

18.5 ± 1.3

19.6 ± 1.3

19.4 ± 1.7

1 < 4, 2 < 4 to 5

0.03

Percent body fat, %

13.8 ± 3.3

13.6 ± 5.7

14.1 ± 3.4

15.8 ± 3.9

16.3 ± 4.2

0.01

LBM, kg

33.3 ± 4.3

37.0 ± 5.2

40.6 ± 4.8

45.1 ± 4.0

44.4 ± 4.4

1,2 < 3 to 5, 3 < 4

0.20

Limb length, cm

Femur

35.0 ± 2.7

37.3 ± 2.7

37.7 ± 2.1

39.3 ± 2.0

38.7 ± 2.1

1 < 3 to 5, 2 < 4

0.05

Lower leg

34.5 ± 2.6

36.6 ± 2.3

37.6 ± 2.0

38.5 ± 1.6

38.5 ± 1.6

1 < 2 to 5, 2 < 4-5

0.08

Muscle thickness, cm

KE

4.1 ± 0.5

4.0 ± 0.5

4.3 ± 0.5

4.8 ± 0.4

4.6 ± 0.4

1,2 < 4 to 5, 3 < 4

0.11

PF

5.7 ± 0.4

5.8 ± 0.5

6.2 ± 0.5

6.6 ± 0.4

6.4 ± 0.5

1,2 < 3 to 5, 3 < 4

0.12

Muscle volume index, cm ³

KE

748 ± 380

986 ± 381

1119 ± 323

1448 ± 258

1342 ± 265

1 < 3 to 5, 2 < 4 to 5, 3 < 4

0.11

PF

582 ± 143

670 ± 150

787 ± 146

899 ± 115

848 ± 142

1,2 < 3 to 5, 3 < 4

0.15

Maximal voluntary joint torque, Nm

KET

103.8 ± 29.7

124.3 ± 37.6

147.7 ± 36.3

168.0 ± 39.4

161.6 ± 39.9

1 < 3 to 5, 2 < 4-5

0.07

PFT

59.9 ± 16.9

84.3 ± 26.4

107.5 ± 39.3

123.4 ± 34.1

100.4 ± 23.8

1 < 2 to 5, 2 < 4

0.09

TQ/MV, Nm/cm ³

KET/MV

0.16 ± 0.06

0.14 ± 0.05

0.14 ± 0.04

0.12 ± 0.03

0.12 ± 0.03

0.01

PFT/MV

0.11 ± 0.03

0.13 ± 0.03

0.14 ± 0.04

0.14 ± 0.03

0.12 ± 0.03

0.01