A Comparison of 3 Different Unilateral Strength Training Strategies to Enhance Jumping Performance and Decrease Interlimb Asymmetries in Soccer Players

Abstract

Purpose: To compare the effects of performing different unilateral strength training interventions on unilateral and bilateral jumping performance and their related asymmetries in young soccer players. Methods: Forty-five young (U-17) male soccer players were randomly assigned to 3 eccentric overload training programs. The first group executed the same volume with both legs starting with the weaker leg (SVW, n = 15); the second group carried out double volume with the weaker leg and also starting with the weaker leg (DVW, n = 15); and the third group performed the same volume with both legs starting with the stronger leg (SVS, n = 15). Jumping-performance assessment included a single-leg horizontal jump test, a triple single-leg horizontal jump test, a bilateral countermovement jump (CMJ) test, and a unilateral CMJ test. Asymmetries were also analyzed in the unilateral jumping tests. Results: CMJ was improved (effect size [ES]: 0.27–0.48) and CMJ asymmetry was possibly reduced (ES: 0.08–0.24) in all groups. Substantial improvements were found in triple hop (ES: 0.52–0.71) in SVW and DVW, and triple-hop asymmetry was substantially decreased (ES: 0.88) in DVW. Between-groups analysis showed a substantially better performance in triple hop and horizontal hop with right leg in SVW and DVW compared with SVS. Conclusions: Unilateral strength training programs were shown to substantially improve bilateral jumping performance, while unilateral jumping was substantially enhanced in the groups that started the training session with the weaker leg. Finally, between-limbs asymmetries in the triple hop were mainly reduced through performing double volume with the weaker leg.

Inter-limb asymmetries are associated with decrements in physical performance in youth elite team sports athletes

“…It has been suggested that existing asymmetries can be reduced if both bilateral and unilateral training methods are programmed concurrently [43]. However, recent research has shown that double the volume on the weaker limb may be effective at reducing between-limb differences during jump tasks [44].…”

Jumping-based Asymmetries are Negatively Associated with Jump, Change of Direction, and Repeated Sprint Performance, but not Linear Speed, in Adolescent Handball Athletes

“…Given the negative association of jumping asymmetries and the reduction of performance tests, it is suggested to apply training interventions with the intention to reduce inter-limb asymmetries. Previous research has highlighted unilateral training such as rear foot elevated split squats and unilateral CMJ as effective methods to reduce imbalances (Gonzalo-Skok et al, 2017), as well as unilateral coordinative training with an isoinertial device (Gonzalo-Skok et al, 2019). These Journal of Human Kinetics -volume 71/2020 http://www.johk.pl suggestions could be useful when programming for youth handball players given the prevalence of unilateral movement patterns in the sport.…”

Influencia de un entrenamiento pliométrico monopodal y bipodal sobre la fuerza explosiva del tren inferior y la corrección de asimetrías en karatekas (Unilateral and bilateral Influence of pliometric training in lower limb power and asymmetry in karatek)

“…Si analizamos en conjunto los datos obtenidos por MO y BI, se puede comprobar como ambos grupos mejoraron su rendimiento, en especial en acciones de SH. A pesar de haberse realizado un entrenamiento sobre la fuerza vertical, se observaron mejoras sobre la fuerza horizontal, de manera similar a otros estudios (Gonzalo-Skok et. al., 2019).…”

“…Una metodología adecuada para poder corregir las asimetrías de las extremidades inferiores es el entrenamiento mediante el salto unilateral Gonzalo-Skok, Moreno, Arjol, Tous & Bishop, 2019). Este tipo de entrenamiento resulta de interés ya que además de corregir la asimetría mejora la velocidad (Mccurdy, Walker, Langford, Kutz, Guerrero, & Mcmillan, 2010).…”