Comparison of load-velocity relationships in two bench press variations: weight stack machine vs Smith machine

Area of Science:

• Sports Science
• Biomechanics
• Exercise Physiology

Background:

• The bench-press (BP) exercise is commonly performed using weight stack machines (WSM).
• Limited research exists on the load-velocity relationship specific to WSM bench-press variations.
• Understanding this relationship is crucial for optimizing training and performance monitoring.

Purpose of the Study:

• To investigate the load-velocity relationship during bench-press exercise using a weight stack machine (WSM).
• To compare the load-velocity relationship between a weight stack machine (WSM) and a Smith machine (SM) during bench-press exercise.

Main Methods:

• Twenty-six young men completed a progressive loading test on a WSM to determine one-repetition maximum (1RM) and load-velocity data.
• Nineteen participants underwent two progressive loading tests, one on a WSM and one on a Smith machine (SM).
• Mean propulsive velocity (MPV) was measured in relation to relative load (%1RM).

Main Results:

• A strong correlation was observed between relative load (%1RM) and MPV during WSM bench-press (R² = 0.97; SEE = 0.07 m/s).
• Significant differences (p < .05) in MPV were found between WSM and SM across various %1RM loads (30-75%).
• The data indicates distinct load-velocity profiles for WSM and SM bench-press exercises.

Conclusions:

• The high predictability of the load-velocity relationship in WSM bench-press allows for effective daily athlete monitoring using MPV.
• Coaches can utilize MPV to track athlete readiness and training adaptations.
• The identified differences between WSM and SM necessitate the use of distinct load-velocity prediction equations for each machine type.