Smith machine counterbalance system affects measures of maximal bench press throw performance

Area of Science:

• Sports Science
• Biomechanics
• Exercise Physiology

Background:

• Counterbalance weight systems are common in assessing explosive resistance exercise performance.
• The impact of these systems on performance metrics remains unclear.

Purpose of the Study:

• To investigate the effect of counterbalance weight systems on smith machine bench press throw performance.
• To analyze the influence on peak force, velocity, and power measurements.

Main Methods:

• 10 men and 14 women performed maximal smith machine bench press throws.
• Tests were conducted with and without a counterbalance system under light and moderate loads.
• Performance variables were measured using a linear accelerometer attached to the barbell.

Main Results:

• Counterbalance systems significantly reduced peak force, velocity, and power (p < 0.001) in both load conditions.
• Load intensity did not alter the magnitude of these reductions.
• Reductions in force, velocity, and power were observed when using the counterbalance system.

Conclusions:

• Counterbalance weight systems decrease accelerometer-based performance measures in bench press throws.
• This is likely due to increased external resistance, creating a discrepancy in load values.
• Avoid using counterbalance systems for accelerometer-based performance assessment in explosive exercises.