Table 2.
Descriptive, M ± SD (n), and inferential analyses for the factor “speed.”
| 2002 to 2005 | 2012 to 2015 | Mean difference [95% CI] | t-statistic | p | Cohen’s d [95% CI] | |
|---|---|---|---|---|---|---|
| 5 m sprint (s) | ||||||
| U13 | 1.18 ± 0.07 (890) | 1.15 ± 0.05 (963) | 0.02 [0.02; 0.03] | 7.75 | < 0.001 | 0.36 [0.27; 0.45] |
| U14 | 1.15 ± 0.07 (998) | 1.12 ± 0.06 (906) | 0.03 [0.02; 0.04] | 10.10 | < 0.001 | 0.46 [0.37; 0.55] |
| U15 | 1.10 ± 0.07 (768) | 1.07 ± 0.06 (869) | 0.04 [0.03; 0.04] | 11.52 | < 0.001 | 0.58 [0.47; 0.67] |
| U16 | 1.07 ± 0.07 (550) | 1.04 ± 0.05 (742) | 0.02 [0.02; 0.03] | 6.47 | < 0.001 | 0.38 [0.25; 0.48] |
| U17 | 1.05 ± 0.07 (474) | 1.03 ± 0.05 (483) | 0.02 [0.02; 0.03] | 5.92 | < 0.001 | 0.38 [0.25; 0.51] |
| U18 | 1.04 ± 0.06 (261) | 1.03 ± 0.05 (283) | 0.01 [0.00; 0.02] | 1.16 | 0.247 | 0.10 [–0.07; 0.27] |
| 10 m sprint (s) | ||||||
| U13 | 2.02 ± 0.09 (890) | 1.99 ± 0.08 (963) | 0.03 [0.02; 0.04] | 7.97 | < 0.001 | 0.37 [0.28; 0.46] |
| U14 | 1.97 ± 0.09 (998) | 1.93 ± 0.08 (906) | 0.04 [0.03; 0.05] | 9.66 | < 0.001 | 0.44 [0.35; 0.53] |
| U15 | 1.88 ± 0.09 (768) | 1.83 ± 0.08 (869) | 0.04 [0.04; 0.05] | 10.65 | < 0.001 | 0.53 [0.43; 0.63] |
| U16 | 1.82 ± 0.08 (550) | 1.79 ± 0.07 (742) | 0.03 [0.02; 0.04] | 6.27 | < 0.001 | 0.36 [0.24; 0.46] |
| U17 | 1.79 ± 0.07 (474) | 1.77 ± 0.06 (483) | 0.03 [0.02; 0.03] | 5.75 | < 0.001 | 0.37 [0.24; 0.50] |
| U18 | 1.77 ± 0.07 (261) | 1.76 ± 0.07 (283) | 0.01 [0.00; 0.02] | 1.66 | 0.097 | 0.14 [–0.03; 0.31] |
| 20 m sprint (s) | ||||||
| U13 | 3.52 ± 0.15 (890) | 3.48 ± 0.14 (963) | 0.04 [0.03; 0.06] | 6.33 | < 0.001 | 0.29 [0.20; 0.39] |
| U14 | 3.42 ± 0.15 (998) | 3.37 ± 0.15 (906) | 0.05 [0.04; 0.07] | 7.80 | < 0.001 | 0.36 [0.27; 0.45] |
| U15 | 3.25 ± 0.15 (768) | 3.17 ± 0.13 (869) | 0.07 [0.06; 0.09] | 10.08 | < 0.001 | 0.50 [0.40; 0.60] |
| U16 | 3.13 ± 0.12 (550) | 3.08 ± 0.11 (742) | 0.04 [0.03; 0.06] | 6.41 | < 0.001 | 0.36 [0.25; 0.47] |
| U17 | 3.07 ± 0.11 (474) | 3.03 ± 0.10 (483) | 0.04 [0.03; 0.05] | 6.19 | < 0.001 | 0.40 [0.27; 0.53] |
| U18 | 3.04 ± 0.11 (261) | 3.01 ± 0.10 (283) | 0.03 [0.01; 0.04] | 3.03 | 0.003 | 0.26 [0.09; 0.43] |
| 5 × 10 m shuttle sprint (s) | ||||||
| U13 | 12.74 ± 0.53 (888) | 12.66 ± 0.52 (965) | 0.08 [0.03; 0.13] | 3.36 | 0.001 | 0.16 [0.07; 0.25] |
| U14 | 12.35 ± 0.52 (996) | 12.35 ± 0.48 (904) | 0.00 [–0.05; 0.04] | –0.16 | 0.869 | –0.01 [–0.10; 0.08] |
| U15 | 11.79 ± 0.50 (764) | 11.67 ± 0.43 (866) | 0.12 [0.07; 0.16] | 5.08 | < 0.001 | 0.25 [0.15; 0.35] |
| U16 | 11.44 ± 0.44 (550) | 11.35 ± 0.39 (741) | 0.09 [0.04; 0.13] | 3.70 | < 0.001 | 0.21 [0.10; 0.32] |
| U17 | 11.29 ± 0.40 (471) | 11.14 ± 0.38 (482) | 0.14 [0.09; 0.19] | 5.71 | < 0.001 | 0.37 [0.24; 0.50] |
| U18 | 11.25 ± 0.39 (261) | 11.02 ± 0.38 (283) | 0.23 [0.16; 0.29] | 6.92 | < 0.001 | 0.59 [0.42; 0.77] |