Sex differences of intermittent elbow flexion power using various loads

Area of Science:

• Exercise Physiology
• Human Movement Science
• Sports Biomechanics

Background:

• Understanding sex differences in muscle function is crucial for tailored training and rehabilitation.
• Intermittent power output tests assess dynamic muscle capabilities under fatiguing conditions.

Purpose of the Study:

• To investigate sex-based differences in muscle power output during intermittent elbow flexion across varying loads.
• To evaluate the reliability and sensitivity of an intermittent power test to load variations and fatigue.

Main Methods:

• 10 young males and 10 females performed intermittent elbow flexion at 30 contractions/min for 1 min using 30%, 40%, and 50% maximal voluntary contraction (MVC) loads.
• Peak power, final power, total power, and fatigue resistance were analyzed, comparing sexes and load conditions.

Main Results:

• Both sexes showed decreased peak power with higher loads; males exhibited a more pronounced decline at 50% MVC.
• Males demonstrated greater sensitivity to load increases in power output decline compared to females.
• The intermittent power output test showed good reliability, with significant sex differences in fatigue resistance at higher loads.

Conclusions:

• Intermittent power output testing, particularly at 50% MVC, effectively measures sustained power and fatigue resistance.
• Significant sex differences exist in the decline of muscle power output under fatiguing conditions, with males experiencing greater fatigue at higher loads.