Effects of a short-term in-season plyometric training program on repeated-sprint ability, leg power and jump performance of elite handball players

This study examined the effects of 8-weeks of in-season lower limb plyometric training on repeated-sprint ability (RSA), leg power and jumping performance in elite male handball players. Twenty-four participants (age 20 ± 0.3 years, body mass 89.1 ± 2.1 kg, height 1.88± 0.07 m, body fat 13.2 ± 1.3%) were randomly assigned to a control group (CG; n = 10, handball training only) or an experimental group (PG; n = 14, biweekly plyometric training, and handball training). The players were tested for RSA using a protocol of 6 x (2 x 15m) shuttle sprints, separated by 20 s of active recovery. Best time in a single trial (RSAbest), fastest total time (RSATT) and performance decrement (RSAdec) were determined. Leg power was determined by the peak power output (PP) during a 7-second all-out cycling test. Jump heights during the squat jump (SJ) and the countermovement jump (CMJ) were measured. Compared to the CG, PG significantly improved the RSAbest (p < 0.01), RSATT (p <0.01) and RSAdec (p < 0.001), average PP (p < 0.01) and all vertical jump performances (p < 0.001 for SJ and p <0.01 for CMJ). Biweekly plyometric training improved several aspects of RSA performance, leg power, and jumping performance during the season in elite male handball players. However, no interaction effect was found between the groups for the repeated sprint ability test (p = 0.062) or relative peak power (p=0.075). Coaches and strength and conditioning professionals should devote additional time for plyometric training in elite male handball players during the season to improve physical performance.