Using Bar Velocity to Predict the Maximum Dynamic Strength in the Half-Squat Exercise.

Area of Science:

• Sports Science
• Biomechanics
• Strength and Conditioning

Background:

• Mean propulsive velocity (MPV) is a key indicator of force production during resistance exercises.
• Understanding the relationship between MPV and load is crucial for performance assessment and training prescription.
• Variability in MPV across different sport disciplines may influence strength testing protocols.

Purpose of the Study:

• To investigate if mean propulsive velocity (MPV) in the half-squat (HS) is consistent across athletes from diverse sports during submaximal and maximal efforts.
• To establish a predictive model for estimating 1-repetition maximum (1-RM) based on MPV at various submaximal loads.

Main Methods:

• Sixty-four male athletes from various sports (football, rugby, soccer, sprinting, jumping, combat sports) participated.
• 1-repetition maximum (1-RM) was determined via a standardized test.
• Half-squats (HS) were performed on a Smith machine at relative 1-RM loads to measure MPV.
• Linear regression analysis was used to correlate MPV with percentage of 1-RM.

Main Results:

• A highly strong linear relationship (R² ≈ .96) was found between MPV and the percentage of 1-RM in the half-squat (HS).
• The derived equation (%HS 1-RM = -105.05 × MPV + 131.75) accurately predicts 1-RM.
• Mean propulsive velocity (MPV) at 1-RM was approximately 0.3 m/s across participants.

Conclusions:

• The established equation provides a highly accurate method for predicting 1-repetition maximum (1-RM) in the half-squat (HS) using a Smith machine.
• This predictive model allows for reliable strength assessment from submaximal loads based on MPV.
• The findings support the use of MPV as a universal metric for strength prediction in diverse athletic populations.