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

Area of Science:

• Sports Science
• Biomechanics
• Exercise Physiology

Background:

• Velocity-based training (VBT) is increasingly used in strength and conditioning.
• Accurate measurement of movement velocity is crucial for effective VBT.
• Linear encoders are common tools for measuring velocity, but their validity needs evaluation.

Purpose of the Study:

• To assess the concurrent validity of the Vitruve linear encoder against the T-Force device.
• To compare measurements of mean propulsive velocity (MPV) and peak velocity (PV) during the free-weight bench press.
• To identify potential discrepancies in velocity measurements across different training intensities.

Main Methods:

• Thirteen resistance-trained men performed free-weight bench press exercises.
• MPV and PV were recorded simultaneously using Vitruve and T-Force devices.
• Statistical analyses included ANOVA, Pearson's correlation, and Bland-Altman analysis (p ≤ 0.05).

Main Results:

• Significant discrepancies were observed between Vitruve and T-Force measurements.
• Vitruve generally reported higher MPV and lower PV, especially at moderate and low intensities.
• Discrepancies increased with higher movement velocities.

Conclusions:

• The Vitruve device is potentially useful for monitoring MPV in the free-weight bench press, particularly at velocities below 0.65 m/s (heavier loads).
• Vitruve may overestimate MPV and underestimate PV at higher velocities (lighter loads).
• Researchers and practitioners should consider these device-specific differences when implementing VBT protocols.