Table 4. Changes in neuromuscular performance for pre- and post-PHV boys after the 8-week jump training intervention (mean ± SD).
Maturity group |
Treatment group |
Condition |
20-m sprint (s) |
CMJ (cm) |
SJ (cm) |
RSI (mm/ms) |
Isokinetic strength (Nm) |
Pre-PHV |
EXP |
Pre |
3.24 ± 0.32 |
21.4 ± 5.2 |
20.0 ± 5.3 |
0.53 ± 0.14 |
101.4 ± 21.4 |
Post |
3.03 ± 0.32 |
23.7 ± 5.7 |
24.0 ± 6.6 |
0.74 ± 0.22 |
114.5 ± 21.7 |
p-value |
p < 0.001 |
p = 0.001 |
p < 0.001 |
p < 0.001 |
p < 0.001 |
Effect size |
0.62 (moderate) |
0.41 (small) |
0.65 (moderate) |
1.00 (large) |
0.58 (moderate) |
CON |
Pre |
3.29 ± 0.46 |
22.7 ± 6.3 |
21.5 ± 6.0 |
0.68 ± 0.31 |
106.6 ± 23.8 |
Post |
3.24 ± 0.46 |
22.4 ± 6.6 |
21.8 ± 6.9 |
0.64 ± 0.25 |
110.5 ± 27.2 |
p-value |
p = 0.156 |
p = 0.491 |
p = 0.729 |
p = 0.353 |
p = 0.050 |
Effect size |
0.11 (trivial) |
-0.05 (trivial) |
0.05 (trivial) |
-0.14 (trivial) |
0.15 (trivial) |
Post-PHV |
EXP |
Pre |
2.99 ± 0.29 |
25.8 ± 5.7 |
25.0 ± 6.4 |
0.71 ± 0.25 |
145.7 ± 28.3 |
Post |
2.89 ± 0.32 |
27.6 ± 7.0 |
26,4 ± 8.0 |
0.79 ± 0.28 |
159.0 ± 28.9 |
p-value |
p = 0.003 |
p = 0.045 |
p = 0.226 |
p = 0.059 |
p = 0.001 |
Effect size |
0.32 (small) |
0.28 (small) |
0.20 (small) |
0.30 (small) |
0.46 (small) |
CON |
Pre |
2.94 ± 0.46 |
25.7 ± 5.1 |
24.1 ± 6.4 |
0.70 ± 0.19 |
150.1 ± 33.4 |
Post |
2.95 ± 0.49 |
25.3 ± 5.4 |
24.5 ± 5.1 |
0.71 ± 0.21 |
148.8 ± 33.4 |
P - value |
p = 0.843 |
p = 0.597 |
p = 0.731 |
p = 0.794 |
p = 0.812 |
Effect size |
-0.02 (trivial) |
-0.08 (trivial) |
0.07 (trivial) |
0.05 (trivial) |
-0.04 (trivial) |
PHV = peak height velocity; CMJ = countermovement jump; SJ = squat jump; RSI = reactive strength index; effects sizes are presented as Cohen’s d.