Effects of concentric and concentric-eccentric resistance training on speed and force in adult soccer players

Abstract

This study investigated the effects of concentric and concentric-eccentric strength training on speed and strength performance in sub-elite soccer players. Thirty-four healthy Czech soccer players were randomly assigned to a concentric group (CONG, n = 13), concentric/eccentric group (ECCG, n = 12), or control group (CG, n = 9). All participants completed the study. Over an 8-week intervention period, the CONG and ECCG groups accomplished 16 training sessions focused on leg curl and leg extension exercises. Speed and strength assessments were performed at baseline and post-intervention. While no significant improvements were observed in speed performance (p > 0.05), both intervention groups demonstrated significant gains in strength parameters. One-repetition maximum (1RM) knee extension increased by 17.5% (CONG, p < 0.001) and 18.3% (ECCG, p < 0.001), and the 1RM knee flexion improved by 10.5% (CONG, p < 0.001) and 12.2% (ECCG, p < 0.001, compared to the CG, with moderate and clear effect sizes. ANOVA analysis revealed significant interaction effects for knee extension 1RM (p < 0.001), knee flexion 1RM (p = 0.022), and isometric knee extension of the dominant leg (p = 0.033). Despite these gains in muscle strength, speed performance showed only minor, non-significant changes, with the CONG group experiencing a 2.8% improvement in the 10-meter sprint. In conclusion, both concentric and concentric-eccentric strength training protocols effectively enhanced lower-limb strength in soccer players, with the concentric-eccentric approach showing slightly better results. However, neither training method significantly improved speed. Coaches should use concentric-eccentric exercises to enhance strength but consider other methods to boost speed and overall performance.

Keywords: Athletic performance; Eccentric training; Force production; Muscle strength; Physical conditioning; Soccer.

Fig. 1

Study design.

Fig. 2

Speed tests design. (a) linear 30-m test with a 10-m split time; (b) 30-meter change-of-direction test.

Fig. 3

Percentage of changes in performance among CONG, ECCG and CG. (A) Sprint tests; (B) Strength test – 1RM and isometric knee extension (angle of 90); (C) Isometric knee extension and flexion, angular velocities of 60°/s (D) Isometric knee extension and flexion, angular velocities of 240°/s. CONG = Concentric Group; ECCG = Concentric/Eccentric Group; CG = control group; S10m = Sprint 10-meter; S10m_B = Spint 10-meters with ball; S30m = Sprint 30-meter; S30m_B = Sprint 30-meter with ball; CODS = Change of Direction Sprint; CODS_B = Change of Direction Sprint with ball; Ex_1RM = Knee Extension One-Maximal Repetition; Flex_1RM = Knee Flexion One-Maximal Repetition; Iso_Ex_DOM = Isometric knee Extension Dominant leg; Iso_Ex_NDOM = Isometric knee Extension non-dominant leg; Ex_DOM_60: Isometric knee Extension with Dominant leg, in anglular velocities of 60°/s; Flex_DOM_60: Isometric knee Flexion with Dominant leg, in anglular velocities of 60°/s; Ex_NDOM_60: Isometric knee Extension with Non Dominant leg, in anglular velocities of 60°/s; Flex_NDOM_60: Isometric knee Flexion with Non Dominant leg, in anglular velocities of 60°/s; Flex_DOM_240: Isometric knee Flexion with Dominant leg, in anglular velocities of 240°/s; Ex_NDOM_240: Isometric knee Extension with Non Dominant leg, in anglular velocities of 240°/s; Flex_NDOM_240: Isometric knee Flexion with Non Dominant leg, in anglular velocities of 240°/s.

Fig. 4

Effet Size graph of CONG, ECCG and CG on (A) Sprint tests; (B) Strength test – 1RM and isometric knee extension (angle of 90); (C) Isometric knee extension and flexion, angular velocities of 60°/s (D) Isometric knee extension and flexion, angular velocities of 240°/s. CONG = Concentric Group; ECCG = Concentric/Eccentric Group; CG = control group; S10m = Sprint 10-meter; S10m_B = Spint 10-meters with ball; S30m = Sprint 30-meter; S30m_B = Sprint 30-meter with ball; CODS = Change of Direction Sprint; CODS_B = Change of Direction Sprint with ball; Ex_1RM = Knee Extension One-Maximal Repetition; Flex_1RM = Knee Flexion One-Maximal Repetition; Iso_Ex_DOM = Isometric knee Extension Dominant leg; Iso_Ex_NDOM = Isometric knee Extension non-dominant leg; Ex_DOM_60: Isometric knee Extension with Dominant leg, in anglular velocities of 60°/s; Flex_DOM_60: Isometric knee Flexion with Dominant leg, in anglular velocities of 60°/s; Ex_NDOM_60: Isometric knee Extension with Non Dominant leg, in anglular velocities of 60°/s; Flex_NDOM_60: Isometric knee Flexion with Non Dominant leg, in anglular velocities of 60°/s; Flex_DOM_240: Isometric knee Flexion with Dominant leg, in anglular velocities of 240°/s; Ex_NDOM_240: Isometric knee Extension with Non Dominant leg, in anglular velocities of 240°/s; Flex_NDOM_240: Isometric knee Flexion with Non Dominant leg, in anglular velocities of 240°/s.