Effects of Three Different Combined Training Interventions on Jump, Change of Direction, Power Performance, and Inter-Limb Asymmetry in Male Youth Soccer Players

Abstract

Background: This study compared the effects of performing different unilateral combined training interventions on diverse vertical and horizontal jumping performance parameters, change of direction, concentric and eccentric mean power, and their associated inter-limb asymmetries in young soccer players.

Methods: Forty-seven young male soccer players (age: 15.5 ± 0.9 years) were distributed into three groups. Two groups performed the same training volume with both legs, beginning with the weaker leg (Stronger Volume Weaker leg group (SVW), n = 14) or with the stronger leg (Stronger Volume Stronger leg group, (SVS), n = 15). The third group executed double the volume with the weaker leg and also commenced with such leg (Double Volume Weaker leg group (DVW), n = 16) during a 10-week period. Pre- and post-intervention tests included a single-leg hop, single-leg lateral hop, triple hop, bilateral and unilateral countermovement jumps, a change of direction speed test, concentric and eccentric mean power during the lateral squat test, and their corresponding asymmetries.

Results: Single-leg hop weaker leg, triple hop weaker leg, and bilateral countermovement jump improvements were achieved in the SVW (ES: 0.29 to 0.46) and DVW (ES: 0.55 to 0.73) groups. Between-groups analysis showed better results in single-leg hop in the SVW and DVW compared to group SVS. The DVW group achieved better improvements in countermovement jump in comparison to groups SVS and SVW.

Conclusions: Groups that started with the weaker leg seemed to achieve a greater volume of significant changes than when starting with the stronger leg. Performing a double volume on the weaker limb does not guarantee further improved performance compared to other groups.

Keywords: between-limbs asymmetry; injury prevention; resistance training.

Figure 1

Participants. SVW, group that started all sets with the weaker leg, training the same volume with both legs; DVW, group that began all sets with the weaker leg, training a double volume of sets with the weaker leg in three exercises; SVS, group that started all sets with the stronger leg, training the same volume with both legs.

Figure 2

Unilateral combined training programme. (A) Lateral squat on a custom-made vibration platform, (B) lateral squat in a Versapulley, and (C) single-legged lateral hop.

Figure 3

Efficiency of the unilateral combined training performing the double volume with the weaker leg starting with the weaker leg (DVW) compared with the unilateral combined training performing the same volume with both legs starting with the weaker leg (SVW) training programme to improve a single-leg hop (SLH) with the stronger and the weaker leg and the corresponding asymmetry (AsySLH), single-leg lateral hop (SLLH) with the stronger and the weaker leg and the corresponding asymmetry (AsySLLH), triple hop (TH) with the stronger and the weaker leg and the corresponding asymmetry (AsyTH), bilateral countermovement jump (CMJ), single-leg countermovement jump (CMJ) with the stronger and the weaker leg and the corresponding asymmetry (AsyCMJ), change of direction (COD) with the stronger and the weaker leg and the corresponding asymmetry (AsyCOD), lateral squat in mean concentric power (ConMean) with the stronger and the weaker leg and the corresponding asymmetry (AsyConMean), and mean eccentric power (MeanEcc) with the stronger and the weaker leg and the corresponding asymmetry (AsyEccMean) (Bars indicate uncertainty in the true mean changes with 90% confidence limits.) Trivial areas were the smallest worthwhile change (see Section 2).

Figure 4

Efficiency of the unilateral combined training performing the same volume with both leg starting with the stronger leg (SVS) compared with the unilateral combined training performing the same volume with both legs starting with the weaker leg (SVW) training programme to improve a single-leg hop (SLH) with the stronger and the weaker leg and the corresponding asymmetry (AsySLH), single-leg lateral hop (SLLH) with the stronger and the weaker leg and the corresponding asymmetry (AsySLLH), triple hop (TH) with the stronger and the weaker leg and the corresponding asymmetry (AsyTH), bilateral countermovement jump (CMJ), single-leg countermovement jump (CMJ) with the stronger and the weaker leg and the corresponding asymmetry (AsyCMJ), change of direction (COD) with the stronger and the weaker leg and the corresponding asymmetry (AsyCOD), an lateral squat in mean concentric power (ConMean) with the stronger and the weaker leg and the corresponding asymmetry (AsyConMean), and mean eccentric power (MeanEcc) with the stronger and the weaker leg and the corresponding asymmetry (AsyEccMean) (Bars indicate uncertainty in the true mean changes with 90% confidence limits.) Trivial areas were the smallest worthwhile change (see Section 2).

Figure 5

Efficiency of the unilateral combined training performing the same volume with both legs starting with the stronger leg (SVS) compared with the unilateral combined training performing the double volume with the weaker leg starting with the weaker leg (DVW) training programme to improve a single-leg hop (SLH) with the stronger and the weaker leg and the corresponding asymmetry (AsySLH), single-leg lateral hop (SLLH) with the stronger and the weaker leg and the corresponding asymmetry (AsySLLH), triple hop (TH) with the stronger and the weaker leg and the corresponding asymmetry (AsyTH), bilateral countermovement jump (CMJ), single-leg countermovement jump (CMJ) with the stronger and the weaker leg and the corresponding asymmetry (AsyCMJ), change of direction (COD) with the stronger and the weaker leg and the corresponding asymmetry (AsyCOD), an lateral squat in mean concentric power (ConMean) with the stronger and the weaker leg and the corresponding asymmetry (AsyConMean), and mean eccentric power (MeanEcc) with the stronger and the weaker leg and the corresponding asymmetry (AsyEccMean) (Bars indicate uncertainty in the true mean changes with 90% confidence limits.) Trivial areas were the smallest worthwhile change (see Section 2).