Table 1. Anthropometric and physical fitness differences according to chronological age and sex in young athletes.
| chronological age | main/interaction effects | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| 12 | 13 | 14 | 15 | p-value (d) | |||||||
| boys | girls | boys | girls | boys | girls | boys | girls | age | sex | age x sex | |
| mean ± SD | mean ± SD | mean ± SD | mean ± SD | mean ± SD | mean ± SD | mean ± SD | mean ± SD | p (d) | p (d) | p (d) | |
| (95% CI) | (95% CI) | (95% CI) | (95% CI) | (95% CI) | (95% CI) | (95% CI) | (95% CI) | ||||
| n = 55 | n = 45 | n = 91 | n = 61 | n = 69 | n = 56 | n = 76 | n = 52 | ||||
| ANTHROPOMETRY | |||||||||||
| standing height [cm] | 161.3 ± 11.7 | 162.2 ± 10.0 | 168.4 ± 10.7 | 165.7 ± 7.5 | 170.4 ± 10.0 | 166.9 ± 8.2 | 179.0 ± 9.9 | 172.2 ± 8.3 | <0.001 | <0.001 | 0.01 |
| (158.7–163.9) | (159.3–165.0) | (166.5–170.5) | (163.3–168.2) | (168.1–172.7) | (164.3–169.4) | (176.8–181.2) | (168.5–173.8) | -0.3 | |||
| n = 54 | n = 45 | n = 91 | n = 59 | n = 68 | n = 56 | n = 76 | n = 52 | -0.94 | -0.34 | ||
| sitting height [cm] | 83.2 ± 6.2 | 84.5 ± 4.9 | 86.7 ± 5.2 | 86.8 ± 4.1 | 87.4 ± 5.5 | 87.6 ± 3.9 | 91.3 ± 5.8 | 89.3 ± 3.8 | <0.001 | 0.872 | 0.104 |
| (81.9–84.5.6) | (83.1–86.1) | (85.7–87.8) | (85.5–88.1) | (86.1–88.7) | (86.3–89.0) | (90.1–92.5) | (87.9–90.7) | -0.01 | -0.3 | ||
| n = 55 | n = 44 | n = 90 | n = 58 | n = 60 | n = 54 | n = 67 | n = 51 | -0.86 | |||
| BMI [kg/m2] | 19.0 ± 3.0 | 19.3 ± 2.5 | 19.4 ± 2.9 | 20.2 ± 2.5 | 20.0 ± 2.7 | 20.9 ± 2.4 | 21.6 ± 3.1 | 20.9 ± 3.7 | <0.001 | 0.538 | 0.035 |
| (18.1–19.9) | (18.4–20.3) | (18.8–20.2) | (19.4–21.1) | (19.2–20.8) | (20.2–21.8) | (20.9–22.4) | (19.9–21.8) | -0.06 | -0.27 | ||
| n = 53 | n = 45 | n = 88 | n = 58 | n = 64 | n = 54 | n = 69 | n = 50 | -0.5 | |||
| body mass [kg] | 50.2 ± 13.0 | 51.4 ± 10.7 | 55.7 ± 13.2 | 55.6 ± 9.4 | 58.4 ± 12.0 | 58.6 ± 8.4 | 69.5 ± 14.2 | 62.3 ± 8.5 | <0.001 | 0.114 | 0.009 |
| (46.8–53.5) | (47.7–55.0) | (53.1–58.3) | (52.4–58.8) | (55.3–61.4) | (55.2–61.9) | (66.1–72.9) | (58.7–65.8) | -0.15 | -0.31 | ||
| n = 53 | n = 44 | n = 88 | n = 60 | n = 64 | n = 54 | n = 69 | n = 49 | -0.88 | |||
| PHYSICAL FITNESS | |||||||||||
| CMJ height [cm] | 26.0 ± 5.6 | 23.6 ± 3.4 | 27.6 ± 4.3 | 25.0 ± 4.4 | 30.4 ± 7.2 | 26.5 ± 4.3 | 36.2 ± 8.8 | 27.4 ± 5.5 | <0.001 | <0.001 | <0.001 |
| (24.2–25.3) | (21.9–25.3) | (26.4–28.8) | (23.5–26.5) | (28.8–31.9) | (25.0–28.0) | (34.7–37.6) | (25.8–29.1) | ||||
| n = 43 | n = 42 | n = 86 | n = 53 | n = 51 | n = 55 | n = 61 | n = 47 | -0.89 | -0.76 | -0.45 | |
| DJ height [cm] | 22.1 ± 5.4 | 22.5 ± 5.0 | 23.8 ± 4.9 | 22.4 ± 5.0 | 26.7 ± 6.6 | 23.4 ± 4.0 | 31.0 ± 7.3 | 24.8 ± 5.0 | <0.001 | <0.001 | <0.001 |
| (20.5–23.8) | (20.9–24.2) | (22.6–24.9) | (21.0–23.9) | (25.1–28.2) | (21.9–24,8) | (29.6–32.3) | (23.3–26.3) | ||||
| n = 43 | n = 42 | n = 86 | n = 52 | n = 51 | n = 55 | n = 62 | n = 49 | -0.77 | -0.47 | -0.43 | |
| DJ ground | 251±101 | 242±53 | 232±61 | 215±42 | 230±67 | 209±29 | 204±35 | 211±35 | <0.001 | 0.078 | 0.287 |
| contact time [ms] | (220–283) | (226–258) | (218–245) | (203–227) | (218–245) | (201–217) | (195–249) | (201–221) | -0.01 | -0.009 | |
| n = 43 | n = 42 | n = 86 | n = 52 | n = 51 | n = 55 | n = 62 | n = 49 | -0.05 | |||
| DJ performance | 0.97 ± 0.39 | 0.96 ± 0.28 | 1.07 ± 0.29 | 1.08 ± 0.30 | 1.27 ± 0.40 | 1.14 ± 0.26 | 1.59 ± 0.50 | 1.21 ± 0.36 | <0.001 | <0.001 | <0.001 |
| index [m/s] | (0.9–1.1) | (0.9–1.1) | (1.0–1.1) | (1.0–1.2) | (1.2–1.4) | (1.0–1.2) | (1.5–1.7) | (1.1–1.3) | |||
| n = 43 | n = 42 | n = 86 | n = 52 | n = 51 | n = 55 | n = 62 | n = 49 | -0.88 | -0.35 | -0.44 | |
| T-test [s] | 11.71 ± 1.08 | 12.14 ± 0.71 | 10.98 ± 0.72 | 11.73 ± 0.94 | 10.82 ± 0.91 | 11.23 ± 0.96 | 10.19 ± 0.75 | 10.92 ± 0.93 | <0.001 | <0.001 | 0.309 |
| (11.4–12.0) | (11.9–12.4) | (10.8–11.2) | (11.5–12.0) | (10.6–11.1) | (11.0–11.5) | (10.0–10.4) | (10.7–11.2) | -0.19 | |||
| n = 34 | n = 42 | n = 75 | n = 52 | n = 51 | n = 51 | n = 62 | n = 48 | -1.08 | -0.66 | ||
| Y-balance [%] | 103.9 ± 8.9 | 101.1 ± 4.6 | 101.3 ± 6.9 | 102.6 ± 6.9 | 103.7 ± 11.2 | 104.3 ± 6.1 | 104.9 ± 10.0 | 101.9 ± 8.1 | 0.5 | 0.286 | 0.263 |
| (101.0–106.9) | (97.8–104.3) | (98.6–104.0) | (99.9–105.3) | (100.9–106.4) | (101.3–106.7) | (102.5–107.3) | (99.4–104.4) | -0.19 | -0.13 | -0.24 | |
| n = 30 | n = 25 | n = 36 | n = 36 | n = 34 | n = 36 | n = 45 | n = 42 | ||||
| Bourban-test [s] | 112.6 ± 50.1 | 102.2 ± 61.5 | 162.4 ± 178.2 | 141.0 ± 163.4 | 152.4 ± 108.1 | 163.0 ± 307.5 | 120.9 ± 44.2 | 103.2 ± 38.1 | <0.001 | 0.515 | 0.869 |
| (65.9–159.4) | (56.5–147.8) | (129.1–195.6) | (100.3–181.7) | (110.5–194.3) | (121.4–204.5) | (82.5–159.2) | (60.0–146.4) | -0.06 | -0.08 | ||
| n = 41 | n = 42 | n = 80 | n = 53 | n = 51 | n = 52 | n = 61 | n = 48 | -0.29 | |||
| Hand grip | 29.2 ± 8.0 | 26.2 ± 4.6 | 33.1 ± 8.7 | 30.5 ± 5.2 | 33.5 ± 9.3 | 32.0 ± 4.5 | 41.3 ± 10.5 | 32.7 ± 5.9 | <0.001 | <0.001 | 0.02 |
| strength [kg] | (26.8–31.6) | (23.8–28.5) | (31.3–34.9) | (28.3–32.7) | (31.3–35.7) | (29.5–34.4) | (39.1–43.5) | (29.9–35.4) | -0.33 | ||
| n = 40 | n = 40 | n = 74 | n = 47 | n = 47 | n = 39 | n = 48 | n = 30 | -0.8 | -0.5 | ||
Data were only calculated if at least 30 participants were available within a subgroup. For the subgroups of 8, 9, 10, 11, 16, 17, and 18 years
old young athletes there were less than 30 participants and, thus, data were not calculated and reported.
BMI = body mass index, CMJ = countermovement jump, DJ = drop jump, SD = standard deviation.