Effects of In-Season Combined Training on Running, Jumping, Agility and Rate of Force Development in Pubertal Soccer Players

The purpose of this study was to compare the effects of in-season combined resistance and pliometric/ sprinttraining with pliometric/ sprintor conventional soccer training alone on field and laboratory measurements expressing explosivity in pubertal soccer players. Thirty one young soccer players ((age (mean ± SD) 14.5 ± 0.52 years; height 172.25 ± 6.66 cm; mass 60.25 ± 6.52 kg) from one team were randomly assigned to either combined-soccer (Combined, n = 14), pliometric-soccer (Pliometric, n = 9) or a control-soccer (Control, n = 8). Two sessions added to habitual soccer regime consisting of one session of resistance exercises combined with one session of plyometric/ sprinttraining for combined group, two sessions of pliometric training for pliometric group and two sessions based on soccer training for control group. Before and after 7-weeks training, isomeric maximal voluntary contraction (IMVC), rate of force development (RFD) in time intervals of 0-10, 0-20…0-250 ms from the onset of contraction, jumping ability, running speed and agility were assessed. Combined group increased significantly their IMVC (from 296.6 ± 74.07 to 339.87 ± 78.9 N.m (p< 0.001) and reduced their 5m-running time (from 1.06 ± 0.07 to 1.01 ± 0.06 sec; p< 0.001) without any significant differences of maximal strength or running performance for other groups. Moreover, combined group revealed a grater improvement of jumping performance mainly in SquatJump (SJ) and CountermovementJump (CMJ) and the RFD in earlier phase than pliometric group with unchanged values for all measurements in control group. We concluded for a more effectiveness of a combined resistance and pliometric/ sprinttraining than only pliometric/ sprintor conventional soccer training for enhancing explosive actions performance and power.