Validity of using perceived exertion to assess muscle fatigue during resistance exercises

• Published in: PeerJ (San Francisco, CA) Vol. 10; p. e13019
• Main Authors: Zhao, Hanye, Nishioka, Takuya, Okada, Junichi
• Format: Journal Article
• Language: English
• Published: United States PeerJ. Ltd 01.03.2022; PeerJ, Inc; PeerJ Inc
• Subjects: Analysis; Anatomy and Physiology; Borg scale; Clinical trials; Elbow; Electromyography; Exercise; Fatigue; Humans; Injuries; Kinesiology; Male; Muscle Fatigue; Perceived exertion; Physical Exertion - physiology; Physical fitness; Physiological aspects; Physiology; Public Health; Regression analysis; Resistance training; Resistance Training - methods; Sport science; Sports Medicine; Surface electromyography; Validity; Velocity; Weight Lifting - physiology; Perceived exertion; Surface electromyography; Muscle fatigue; Borg scale; Resistance training
• ISSN: 2167-8359; 2167-8359
• DOI: 10.7717/peerj.13019

The rating of perceived exertion (RPE) is correlated with physiological variables. The purpose of this study was to assess the validity of using the Borg CR-10 scale and velocity to predict muscle fatigue assessed by surface electromyography during single joint resistance exercises. Fifteen healthy males underwent different fatigue levels of unilateral elbow flexion (EF) and knee extension (KE), consisting of low, medium, and high volumes at 65% of their one-repetition maximum. The RPEs, spectral fatigue index (SFI), and mean velocity of the experimental exercises were assessed throughout the trials. Significant differences in overall RPE ( < 0.001) and average SFI ( < 0.001) were observed between the conditions in both exercises. Significant changes in RPE and SFI ( < 0.001) were observed throughout the EF, whereas a SFI increase ( < 0.001) was only observed at the end point of KE. Multiple regression analyses revealed two significant models ( < 0.001) for the prediction of muscle fatigue during EF (R = 0.552) and KE (R = 0.377). Muscle fatigue resulted in similar increases in perceptual responses, demonstrating that RPE is useful for assessing fatigue when resistance exercise is performed. However, velocity changes may not reflect muscle fatigue correctly when exercise is no longer performed in an explosive manner. We recommend combining RPE responses with velocity changes to comprehensively assess muscle fatigue during clinical and sports situations.