*Performance Parameters*

No statistical di fferences were observed between groups in baseline values (Table 1). Group × time interactions were found for all the examined parameters (*p* < 0.038) except for 10 m sprint speed (*p* = 0.709) (Table 3). Comparison of changes in performance values between the TG and CG showed large e ffect sizes, indicating improvement in one- and two-legs countermovement jumps, drop jump, single-leg jumping agility, and round-o ff performance time in the TG (Table 3).

In particular, significant group × time interactions were observed for two- and one-leg countermovement jumps height (*p* = 0.004, η2 = 0.329 and *p* = 0.002, η2 = 0.351, respectively) with the post hoc showing an improvement only for the TG (*p* = 0.032, *d* = 1.20 and *p* = 0.003, *d* = 0.73, respectively) (Table 3). Significant group × time interactions were also observed in round-o ff performance time and single-leg jumping agility (*p* = 0.004, η2 = 0.328 and *p* = 0.001, η2 = 0.398, respectively) with the post hoc test showing improvement only for the TG (*p* = 0.0109, *d* = 1.20 and *p* = 0.001, *d* = 2.15). A significant group × time interaction was also observed for drop-jump (*p* = 0.038, η2 = 0.189) with the post hoc test showing improvement only or the TG (*p* = 0.008, *d* = 0.98).


**Table 3.** Changes in the examined parameters following 10 weeks of intervention in the training group (TG, *n* = 12) and the control group (CG, *n* = 11).

*Note*: CMJ: counter movement jump; R + L CMJ: sum of the right- and the left-leg counter movement jumps; DJ: drop jump.

The percent changes in performance for the TG and the CG are presented in Figure 1. TG improved CMJ performance with one-leg (11.5% ± 10.4%, *p* = 0.002) and two-legs (8.2% ± 8.8%, *p* = 0.004), DJ performance (14.4% ± 12.6%, *p* = 0.038), single-leg jumping agility (13.6% ± 5.2%, *p* = 0.001), and sport-specific performance (8.8% ± 7.4%, *p* = 0.004), but not 10 m sprint performance (2.4% ± 6.6%, *p* = 0.709). All performance changes for the CG were not significant (*p* = 0.41 to 0.98).

**Figure 1.** Percentage of change pre−post intervention in the examined parameters in the training and the control groups; CMJ: counter movement jump; R + L CMJ: sum of right– and the left−leg counter movement jumps; DJ: drop jump; \*\* *p* < 0.01 between training and control groups.
