Validity of using perceived exertion to assess muscle fatigue during bench press exercise

BACKGROUND: Muscle fatigue is nearly unavoidable during resistance exercise, yet evaluating it in such circumstances can be challenging. OBJECTIVE: This study aimed to evaluate the validity of using the rating of perceived exertion (RPE) as a measure of muscle fatigue during non-explosive bench press (BP) exercise. METHODS: Fifteen male collegiate athletes participated in three BP tasks set at 65% of their one-repetition maximum. The RPE, spectral fatigue index (SFI), and velocity loss were measured across different experimental conditions. RESULTS: Significant effects were observed across different experimental conditions for the overall RPE, average velocity loss, and average SFI (all p< 0.001). As the lifting tasks progressed, there were significant increases in the RPE, velocity loss, and SFI (p< 0.001). Additionally, significant differences were observed between the experimental conditions in the RPE (p< 0.001), SFI (p< 0.001), and velocity loss (p< 0.01). A significantly stronger (p< 0.05) correlation was observed between the RPE and SFI (r= 0.68, df= 117, p< 0.001) than between the velocity loss and SFI (r= 0.51, df= 117, p< 0.001). CONCLUSIONS: The corresponding changes observed in the RPE, velocity loss, and SFI suggest that both the RPE and velocity loss can be used as indicators of muscle fatigue during non-explosive BP exercise. However, due to the strong correlation between the RPE and SFI, RPE is more effective for reflecting muscle fatigue in non-explosive resistance exercise settings. Regarding ease of use, the RPE is more suitable than velocity loss for assessing muscle fatigue in training scenarios.