What effect does increased pulse frequency have on muscle fatigue?

Increased pulse frequency typically leads to muscle fatigue. When the frequency of electrical stimulation applied to the muscle is increased, it causes more rapid contractions. These rapid contractions do not allow sufficient time for the muscle to relax and recover in between stimuli. As a result, the muscle fibers become fatigued more quickly due to the sustained demand for energy and the accumulation of metabolic byproducts like lactic acid.

This rapid firing can deplete the muscle’s stores of ATP (adenosine triphosphate), which is essential for muscle contraction. Additionally, the continuous activation can lead to a reduced ability of the muscle to generate force over time, contributing to the sensation of fatigue. Thus, an increase in pulse frequency correlates directly with an increase in muscle fatigue, confirming that the correct understanding of this relationship is that fatigue indeed increases with higher stimulation frequency.