The effects of two preseason periodizations on peak torque of knee extensors and flexors of a Polish first league soccer team.

The study aimed to compare the effectiveness of two resistance training load progression methods-linear and step-on peak torque and power of knee extensors and flexors during the preseason of a Polish First League soccer team across two seasons. Differences between dominant and non-dominant limbs were analyzed, with progression tracked by tempo of movement and time under tension. Velocity-based training with a linear transducer ensured standardized intensity. Sixteen players from the same club participated in both seasons: 2021/2022 (linear) and 2022/2023 (step). Three-way ANOVA showed a significant leg × training × mesocycle interaction in the knee extensor and flexor peak torque. The post hoc test showed significant differences in peak torque between the dominant and nondominant legs during both progressive load methods - 2021/2022 and 2022/2023 seasons, both before and after the training intervention (p < 0.05). Knee extensors: The dominant leg showed higher values ​​compared to the non-dominant leg. However, there were no significant differences during the 2022/2023 season (p > 0.05). Knee flexors: No difference in peak torque values ​​between the dominant and non-dominant legs before the training intervention - 2022/2023 season. The conducted studies clearly indicate a greater effectiveness of the step load progression, however it also significantly affected bilateral asymmetry.