Table 3. Anthropometrics and performance variables before and after 7 weeks of plyometric training in young soccer players.
| Variable |
Control (n=14) |
G30 (n=13) |
G60 (n=13) |
G120 (n=11) |
| Countermovement jump (cm) |
| Before |
22.1 (4.9) |
22.2 (4.1) |
21.9 (2.1) |
21.7 (4.4) |
| After |
21.9 (4.7) |
24.0 (5.6) |
23.9 (3.1) |
23.5 (5.4) |
| Training effect (%) |
-.9 (-1.9, +1.9) |
+8.1 (+1.3, +16.8) |
+9.1 (+1.9, +21.9) |
+8.5 (+1.8, +18.6) |
| Effect size |
-.1 (-.34, +.24) |
+.49 (+.24, +.79)* |
+.58 (+.29, +.88)* |
+.55 (+.27, +.82)* |
| P value Pre-Post |
.4 |
.04 |
.02 |
.03 |
| 20 cm drop jump reactive strength index (mm/ms) |
| Before |
.78 (.2) |
.77 (.21) |
.75 (0.2) |
.75 (.3) |
| After |
.85 (.2) |
1.03 (.2) |
1.01 (0.2) |
1.02 (.3) |
| Training effect (%) |
+8.1 (-14.4, +24.7) |
+33.2 (+14.4, +76.1) |
+35.3 (+15.9, +74.3) |
+36.6 (+14.3, +81.1) |
| Effect size |
+.27 (-.31, +.59)* |
+.81 (+.38, +1.27)** |
+.89 (+.48, +1.22)** |
+.86 (+.39, +1.33)** |
| P value Pre-Post |
.09 |
.0004 |
.0004 |
.0002 |
| 40 cm drop jump reactive strength index (mm/ms) |
| Before |
.75 (.3) |
.74 (.3) |
.74 (.2) |
.73 (.3) |
| After |
.84 (.2) |
1.03 (.3) |
1.02 (.3) |
1.06 (.3) |
| Training effect (%) |
+12.9 (-9.0, +28.7) |
+39.0 (+8.9, +66.4) |
+38.9 (+9.0, +65.3) |
+46.4 (+15.4, +79.7) |
| Effect size |
+.48 (-.36, +.72)* |
+.86 (+.39, +1.6)** |
+.88 (+.29, +1.41)** |
+.98 (+.44, +1.51)** |
| P value Pre-Post |
.1 |
.0001 |
.0003 |
.0001 |
| 20m (s) |
| Before |
4.3 (.3) |
4.4 (.5) |
4.3 (.2) |
4.3 (.4) |
| After |
4.5 (.4) |
4.4 (.3) |
4.3 (.3) |
4.4 (.4) |
| Training effect (%) |
+6.6 (+2.9, +9.6) |
-1.8 (-3.9, +0.7) |
+.3 (-1.2, +1.9) |
+.4 (-3.0, +3.3) |
| Effect size |
+.65 (+.44, +1.32)** |
-.3 (-.68, +0.28)* |
+.09 (-.19, +0.33) |
+.13 (-.33, +.60) |
| P value Pre-Post |
.03 |
.09 |
.8 |
.2 |
| Change of direction speed (s) |
| Before |
7.4 (.5) |
7.4 (.6) |
7.4 (.5) |
7.4 (.7) |
| After |
7.3 (.4) |
7.0 (.4) |
7.1 (.5) |
7.0 (.6) |
| Training effect (%) |
-2.6 (-5.0, +2.5) |
-6.5 (-10.9, -2.3) |
-5.2 (-9.9, -1.1) |
-6.9 (-12.1, -2.4) |
| Effect size |
-.4 (-.77, +0.45)* |
-1.03 (-1.42, -.4)** |
-.87 (-1.5, -.29)** |
-1.04 (-1.6, -.49)** |
| P value Pre-Post |
.1 |
.03 |
.03 |
.02 |
| Maximal kicking distance (m) |
| Before |
20.0 (5.3) |
19.7 (7.4) |
18.9 (5.0) |
19.3 (7.0) |
| After |
20.1 (5.8) |
22.0 (8.9) |
21.8 (4.1) |
21.6 (7.0) |
| Training effect (%) |
+1.1 (-2.4, +6.6) |
+11.3 (+2.3, +23.4) |
+15.0 (+2.7, +29.9) |
+12.6 (+4.0, +24.1) |
| Effect size |
+.01 (-.09, +.21) |
+.39 (-.03, +.68)* |
+.49 (-.01, +.88)* |
+.43 (+.08, +.77)* |
| P value Pre-Post |
.8 |
.03 |
.02 |
.03 |
** moderate standardized effect. P value Pre-Post: P value of pre to post training change.* small standardized effect;Before and after values are means (± SD). Training effect and effect size values are mean (90% confidence limits). G30, G60, and G120: 30 s, 60 s, and 120 s rest interval groups, respectively;
