Relationship between neuromuscular profile and total volume of resisted sprint training in male professional soccer players

Purpose This 11-week study aimed to correlate the neuromuscular profile and the total volume of resisted sprint training (RST) under different velocity loss (VL) magnitudes in male professional soccer players. Methods Seventeen soccer players (age 25.8 +/- 4.3 years; height 180.0 +/- 8.6 cm; weight 77.7 +/- 9.7 kg) were randomly allocated into two training groups, who trained at distinct percentages of VL: 10% of VL (G10, n = 8) or 20% of VL (G20, n = 9). The velocity-based sled training consisted of 20 m resisted sprints executed with a progressive loading increase (45-65% of body-mass). Sprint times (10 m and 20 m), vertical jump height [countermovement jump (CMJ) and squat jump (SJ)], knee flexion and extension peak torque, as well as isometric rate of torque development, and lower limb lean mass were correlated with the total volume of RST performed by G10 and G20 groups. Results The G10 performed 31% less repetitions and total RST distance than G20 (p = 0.002). Significant negative Pearson's correlations (large-to-very large) were observed between total volume performed by G10 and CMJ height [r = - 0.85, confidence interval at 95% (95% CI) = - 0.98 to - 0.58, p = 0.02, Cohen's D effect size (ES) = 0.41] as well as SJ height (r = - 0.90, 95% CI - 0.99 to - 0.66, p = 0.005, ES = 0.80), and knee extension concentric peak torque (r = - 0.69, 95% CI - 0.99 0.91, p = 0.05, ES = 0.03). No further correlation was found (p > 0.05). Conclusions When lower magnitudes of VL were used during training sessions (10%), the stronger and more powerful players performed lower volume of RST. Interestingly, this relationship is not confirmed when higher magnitudes of VL (20%) are prescribed (greater fatigue incidence).