Hydraulic Resistance Device for Force, Power, and Force–Velocity–Power Profile Assessment During Resisted Sprints with Different Overloads ^†

This study aimed to evaluate the ability of a hydraulic resistance device (HRD) to assess the force and power output and force–velocity–power profile of short sprints, while examining the effects of hydraulic overload on these outcomes. Twenty-eight amateur athletes performed 20 m sprints under minimal (MiL), moderate (MoL), and high (HiL) overloads. Sprint velocity was measured with the HRD, while resistance force (F_r) was assessed from the pressure via the HRD and from the reaction force via the force plate (FP). Using velocity and F_r during the sprints, maximal velocity (v_max), average horizontal force (F_avg), average power (P_avg), and FvP profile variables (F₀, v₀, and P_max) were calculated. A two-way ANOVA analysed the effects of overload and calculation method. In addition, a correlation between the HRD and FP measurements was evaluated. For all variables, very high to excellent correlation between the HRD and FP was observed (r ≥ 0.96). However, the F_avg, P_avg, F₀, and P_max calculated by the HRD were lower than the FP across all overloads (η² ≥ 0.51; p < 0.001). Regardless of the method used, F_avg, P_avg, and F₀ were highest at HiL (η² ≥ 0.38; p < 0.001), and v₀ was highest at MiL (η² = 0.35; p < 0.001), whereas overload had no significant effect on P_max (η² = 0.01; p = 0.770). The HRD is a feasible means for monitoring force and power output during hydraulic resisted sprints but should not be directly compared to other resistance devices. HiL produced the highest F_avg, P_avg, and F₀ and may be optimal for increasing power output and improving acceleration performance.