How Does Instability Affect Bench Press Performance? Acute Effect Analysis with Different Loads in Trained and...

Area of Science:

• Sports Science
• Biomechanics
• Exercise Physiology

Background:

• Athletic performance relies on stability during dynamic movements like throws and jumps.
• A lack of classification exists for unstable training devices and their impact on performance.
• The influence of instability training on athletes' subjective experience is not well understood.

Purpose of the Study:

• To analyze power and speed parameters during bench press using various stable and unstable conditions.
• To compare performance variables across different load intensities (40%, 60%, 80% of 1RM) in each condition.
• To investigate the effects of training status (trained vs. untrained) on these performance variables.

Main Methods:

• Bench press performance was assessed in five conditions: stable (SB), asymmetric load (AB), unstable load (UB), Fitball (FB), and Bosu ball (BB).
• Mean propulsive speed (MPS), maximum speed (MS), and power (PW) were measured using an inertial dynamometer.
• Thirty male participants, including 15 trained and 15 untrained individuals, completed the tests.

Main Results:

• Stable execution (SB) yielded the best performance, followed by asymmetric load (AB), unstable load (UB), Fitball (FB), and Bosu ball (BB).
• FB and BB conditions showed significant performance decrements (7-23%) compared to SB.
• No significant differences in performance were observed between trained and untrained groups, except for MS at 60% 1RM where trained individuals performed better.

Conclusions:

• Executing the bench press on unstable surfaces like Fitballs or Bosu balls is not recommended for optimizing power and speed.
• Asymmetric load (AB) and unstable load (UB) bench press may enhance stabilization training without substantial performance reduction.
• Athletic experience does not appear to be a critical factor influencing performance outcomes in these unstable conditions.