Specific Adaptations in Performance and Muscle Architecture After Weighted Jump-Squat vs. Body Mass Squat Jump Training in Recreational Soccer Players

Abstract

Coratella, G, Beato, M, Milanese, C, Longo, S, Limonta, E, Rampichini, S, Cè, E, Bisconti, AV, Schena, F, and Esposito, F. Specific adaptations in performance and muscle architecture after weighted jump-squat vs. body mass squat jump training in recreational soccer players. J Strength Cond Res 32(4): 921-929, 2018-The aim of the present study was to compare the effects of weighted jump-squat training (WJST) vs. body mass squat jump training (BMSJT) on quadriceps' muscle architecture, lower-limb lean-mass (LM) and muscle strength, performance in change of direction (COD), and sprint and jump in recreational soccer players. Forty-eight healthy soccer players participated in an offseason randomized controlled trial. Before and after an 8-week training intervention, vastus lateralis pennation angle, fascicle length, muscle thickness, LM, squat 1RM, quadriceps and hamstrings isokinetic peak torque, agility T-test, 10-and 30-m sprints, and squat-jump (SJ) were measured. Although similar increases were observed in muscle thickness, fascicle length increased more in WJST (Effect size [ES] = 1.18, 0.82-1.54) than in BMSJT (ES = 0.54, 0.40-0.68), and pennation angle increased only in BMSJT (ES = 1.03, 0.78-1.29). Greater increases in LM were observed in WJST (ES = 0.44, 0.29-0.59) than in BMSJT (ES = 0.21, 0.07-0.37). The agility T-test (ES = 2.95, 2.72-3.18), 10-m (ES = 0.52, 0.22-0.82), and 30-m sprints (ES = 0.52, 0.23-0.81) improved only in WJST, whereas SJ improved in BMSJT (ES = 0.89, 0.43-1.35) more than in WJST (ES = 0.30, 0.03-0.58). Similar increases in squat 1RM and peak torque occurred in both groups. The greater inertia accumulated within the landing phase in WJST vs. BMSJT has increased the eccentric workload, leading to specific eccentric-like adaptations in muscle architecture. The selective improvements in COD in WJST may be related to the increased braking ability generated by the enhanced eccentric workload.

The Increased Effectiveness of Loaded Versus Unloaded Plyometric Jump Training in Improving Muscle Power, Speed, Change of Direction, and Kicking-Distance Performance in Prepubertal Male Soccer Players

“…These results corroborate those of Coratella et al 14 who studied the effects of weeks of loaded (30% of squat 1RM) and unloaded jump-squat training in recreationally trained male soccer players (aged 21 years). These researchers reported improvements in sprint performance over 10-m and 30-m in the loaded squat-jump group only (ES=0.52 for both 10 and 30-m), attributing this finding to the greater eccentric load imposed by the LPJT programme.…”

“…The CoD performance improvements following UPJT were expected considering the extensive empirical studies supporting the effectiveness of this type of training in youth populations. 21,25,26 Recently, Coratella et al 14 Sheppard and Young, 27 suggest that PJT can improve eccentric strength of the thigh muscles, an important determinant of performance during the deceleration phase of CoD movements. 28 Improvements in CoD performance following PJT could occur due to the interaction of several training-related neuromuscular adaptations including the improvement of neural drive to agonist muscles, patterns that enable athletes to rapidly switch between deceleration and acceleration motions (i.e., higher efficiency of the stretch-shortening cycle), and muscle activation strategies (i.e., inter-and intra-muscular coordination).…”

“…The optimal PJT strategy that may elicit the largest physical fitness improvements in this population is still under debate. With reference to previous research 12, 14,16 , we hypothesised that LPJT would induce larger improvements on measures of muscle power, speed, CoD and kicking-distance performance than UPJT in prepubertal male soccer players.…”

“…12,13 Due to this, a potential way to enhance adaptations to PJT is to use extra-loads additional to body mass (LPJT). [14][15][16] In this context, Rosas et al 16 compared the effects of a 6-week LPJT programme, using handheld dumbbells, with UPJT on jump performances and maximal ball kicking-velocity in young male soccer players (aged 12 years). These authors reported small performance improvements in countermovement jump (CMJ), horizontal jumps, reactive strength index and maximal kickingvelocity (effect size [ES]=0.27 to 0.47), with larger effects seen in LPJT than in UPJT.…”

“…18 Further to the above, Kobal et al 15 compared the effects of 6 weeks of LPJT, using handheld dumbbells, and UPJT on measures of muscle power and speed in elite young male soccer players (aged 16 years), reporting better improvements in vertical jumping performance in LPJT group (Δ9.4% and 8.4% for squat jump [SJ] and CMJ, respectively, in LPJT group; Δ4.6% and 5% for the SJ and CMJ in UPJT group, respectively). Recently, Coratella et al 14 studied the effects of 8 weeks of LPJT or UPJT in recreationally trained male soccer players (aged 21 years). These authors found that CoD and sprint performances improved to a larger extent in the LPJT group (ES=2.95, 0.52, and 0.52 for T-test, 10-m and 30-m sprint tests, respectively) compared to the UPJT group (ES= 0.04, 0.10, and 0.06 for T-test, 10-m and 30-m sprint tests, respectively).…”