The effect of augmented feedback with velocity-based training on post-activation performance enhancement in college soccer players

This study aimed to investigate the effects of visual augmented feedback with velocity-based training (VBT) on post-activation performance enhancement (PAPE) in college soccer players. Eighteen male college soccer players participated in a crossover trial. They were randomly assigned to receive three resistance activation protocols (85% of 1RM barbell squats) to induce PAPE. The three activation protocols consisted of a visual feedback protocol based on 5%VL (VF5%VL), a fixed 12-repetition visual feedback protocol (VF12reps.), and a fixed 12-repetition protocol without visual feedback (NVF12reps.). We assessed the PAPE using 20-meter sprint performance metrics (5-meter and 20-meter sprint times, maximum speed, maximum acceleration) at 4, 8, 12, and 16 min following barbell squat activation in soccer players. We analyzed those metrics using two-way repeated measures ANOVA and calculated the effect size$$\:{\:(\eta\:}_{p}^{2}$$). The$$\:{\:\eta\:}_{p\:}^{2}$$were categorized as trivial ($$\:{\eta\:}_{p}^{2\:}$$< 0.01), small (0.01 ≤$$\:\:{\eta\:}_{p\:}^{2}$$< 0.06), moderate (0.06 ≤$$\:\:{\eta\:}_{p\:}^{2}$$< 0.14), and large ($$\:{\eta\:}_{p}^{2\:}$$≥ 0.14) effects. We also calculated the smallest worthwhile change (SWC) to evaluate practical meaningfulness. SWC was defined as 0.2 × the between-subject standard deviation (SD) of the control condition (NVF12reps.), and changes ≥ SWC were interpreted as practically meaningful. p < 0.05 was statistically significant. There was no time × protocol interactions for the metrics (p > 0.05). The main effect of protocol was found for 5-m sprint time (F = 4.553, p = 0.037, $$\:{\:\eta\:}_{p}^{2\:}$$= 0.211) and maximum acceleration (Amax) (F = 3.680, p = 0.036, $$\:{\:\eta\:}_{p}^{2\:}$$ = 0.178). In pairwise comparisons, VF5%VL showed a significant improvement compared to NVF12reps. in 5-meter sprint time (mean difference = − 0.04 s, p = 0.019, 95% CI: −0.067 to − 0.007) and Amax (mean difference = 0.28 m/s², p = 0.018, 95% CI: 0.053 to 0.500). VF12reps. showed no significant difference compared to NVF12reps. (5-meter sprint time: p = 0.067; Amax: p = 0.241). No significant differences between VF5%VL and VF12reps. (5 m: p = 0.616; Amax: p = 0.133). No significant differences were observed for 20-meter sprint time (p = 0.221, $$\:{\:\eta\:}_{p}^{2\:}$$ = 0.090) or maximum speed (Vmax) (p = 0.380, $$\:{\:\eta\:}_{p}^{2\:}$$ = 0.060). This study demonstrates that visual augmented feedback VBT can meaningfully enhance sprint start acceleration in soccer players. However, its effectiveness in improving maximal sprint speed remains inconclusive, warranting further investigation into physiological mechanisms.