Validity of a New Portable Sensor to Measure Velocity-Based Resistance Training

This study evaluated the concurrent validity of the Vitruve linear encoder compared to the T-Force device for measuring mean propulsive velocity (MPV) and peak velocity (PV) during the free-weight bench exercise. Twelve resistance-trained men participated in three sessions, during which MPV and PV were recorded sim-ultaneously by both devices. The data were analyzed using one-way ANOVA, Pearson's correlation, Bland-Altman analysis, and effect size calculations, with statistical significance set at p ≤ 0.05. The results showed discrepancies between the Vitruve and T-Force devices across different intensity levels. Specifically, the Vitruve device generally reported higher MPV and lower PV values, particularly at moderate and low in-tensities. Vitruve was deemed useful for MPV measurements, especially at velocities below 0.65 m/s during free-weight bench press exercises. In conclusion, the Vitruve device overestimated MPV and underestimated PV at moderate and low loads (> 0.65 m·s⁻¹), with the discrepancies increasing as velocity rose. It can provide valuable data for monitoring and assessing resistance training programs focused on MPV at heavier loads (< 0.65 m·s⁻¹). Researchers and practitioners should take these findings into account when incorporating the Vi-truve into velocity-based strength training protocols.