Neuromuscular responses of recreationally active women during a sustained, submaximal isometric leg extension muscle action at a constant perception of effort

Abstract

The current findings indicated that it was necessary to reduce force to maintain RPE = 5. The neuromuscular and force responses supported the RPE clamp model and suggested that force was initially regulated by anticipatory feedforward mechanisms and then altered by afferent feedback.

Sex-Related Differences in Performance Fatigability Independent of Blood Flow Following a Sustained Muscle Action at a Low Perceptual Intensity

“…Ratings of perceived exertion (RPE) are often integrated into resistance training to prescribe exercise intensity [13,16,21,30,31]. Little is known, however, regarding the specific relationships between RPE and physiological mechanisms associated with fatigue resulting from resistance exercise [13,16,21,29,37].…”

“…Ratings of perceived exertion (RPE) are often integrated into resistance training to prescribe exercise intensity [13,16,21,30,31]. Little is known, however, regarding the specific relationships between RPE and physiological mechanisms associated with fatigue resulting from resistance exercise [13,16,21,29,37]. A limited number of previous aerobic [6,14,19] and resistance [21,29] exercise studies have utilized the RPE clamp model [39] to examine fatigue-induced changes in various physiological outcome variables such as blood pressure, oxygen consumption, neuromuscular parameters, power output, and force.…”

“…Little is known, however, regarding the specific relationships between RPE and physiological mechanisms associated with fatigue resulting from resistance exercise [13,16,21,29,37]. A limited number of previous aerobic [6,14,19] and resistance [21,29] exercise studies have utilized the RPE clamp model [39] to examine fatigue-induced changes in various physiological outcome variables such as blood pressure, oxygen consumption, neuromuscular parameters, power output, and force. A common outcome of both the aerobic [6,14,19] and resistance exercise [21,29] investigations is that it is necessary to reduce power output or force, respectively, to maintain a constant RPE.…”

“…Our recent investigation in women [21] utilized the RPE clamp protocol to examine the unique neuromuscular patterns of responses for muscle actions anchored to RPE. Typically, in response to fatigue resulting from a muscle action anchored to force, there are changes in motor unit activation strategies that include increases in muscle activation [electromyography (EMG) amplitude (AMP)] and motor unit recruitment [mechanomyography (MMG) 1 3 AMP], as well as decreases in action potential conduction velocity [EMG mean power frequency (MPF)] and global motor unit firing rate (MMG MPF) [2,12].…”

“…Typically, in response to fatigue resulting from a muscle action anchored to force, there are changes in motor unit activation strategies that include increases in muscle activation [electromyography (EMG) amplitude (AMP)] and motor unit recruitment [mechanomyography (MMG) 1 3 AMP], as well as decreases in action potential conduction velocity [EMG mean power frequency (MPF)] and global motor unit firing rate (MMG MPF) [2,12]. Our previous results demonstrated, however, that when force is anchored to RPE, there were increases in MMG AMP, but no simultaneous changes in EMG AMP or EMG MPF [21]. Previous studies have suggested that anchoring to both RPE [21] and force [2,12] result in fatigue-induced decreases in maximal voluntary isometric contraction (MVIC).…”