Background: 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. Methods: 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. Results: Significant differences in overall RPE (p < 0.001) and average SFI (p < 0.001) were observed between the conditions in both exercises. Significant changes in RPE and SFI (p < 0.001) were observed throughout the EF, whereas a SFI increase (p < 0.001) was only observed at the end point of KE. Multiple regression analyses revealed two significant models (p < 0.001) for the prediction of muscle fatigue during EF (R² = 0.552) and KE (R² = 0.377). Conclusions: 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.

The rating of perceived exertion (RPE) scale has been found to reflect physiological responses, and this study aimed to assess the validity of using the Borg CR-10 scale and velocity loss to evaluate muscle fatigue quantified by surface electromyography during back squat (BS) exercise. A total of 15 collegiate male athletes underwent three non-explosive BS tasks comprising low, medium, and high volumes at 65% of their one-repetition maximum. RPEs, spectral fatigue index (SFI), and velocity loss during BS exercise were assessed throughout the trials. Significant differences in overall RPE (p < 0.001) and average SFI (p < 0.05) were observed between the conditions, whereas no significant difference was observed in average velocity loss. Significant increases in RPE and SFI (p < 0.001) were observed within the exercise process, whereas a significant increase in velocity loss was not observed. Correlation analyses indicated a significant correlation between RPE and SFI obtained during exercise (r = 0.573, p < 0.001). However, no significant correlation was observed between velocity loss and SFI. These results demonstrated that RPE could be used as a muscle fatigue predictor in BS exercise, but that velocity loss may not reflect muscle fatigue correctly when participants cannot and/or are not required to perform BS explosively. Furthermore, practitioners should not use velocity loss as a muscle fatigue indicator in some resistance exercise situations, such as rehabilitation, beginner, and hypertrophy programs.

Dancesport is performed in high-heeled shoes. Dancesport athletes may have a higher prevalence and incidence of ankle sprains, which can affect their performance. However, the occurrence of ankle sprains among dancesport athletes remains unclear. This study aimed to determine the prevalence and incidence of ankle sprains among elite dancesport athletes and to investigate the related information. We conducted a mixed descriptive epidemiological study (cross-sectional and longitudinal) involving 198 elite adolescent dancesport athletes, using past medical records and questionnaires administered to the participants. Data on the occurrence of ankle sprains among all participants were compiled using medical records and information on injury mechanisms, missed days, severity types, and countermeasures for ankle sprains were collected. The prevalence of chronic ankle instability (CAI) among the participants was assessed using a questionnaire. Following the initial survey, we conducted a one-year follow-up study to investigate the incidence of ankle sprains, incidence rate per 1000 exposure hours, and recurrence of ankle sprains. The cross-sectional study and longitudinal study included 198 participants and 92 elite dancesport athletes, respectively. The prevalence of ankle sprains and CAI was 49.5% and 45.1%, respectively. Of all ankle sprains, 88% were medial injuries. The most common injury mechanisms were turning (46.9%) and jumping (46.9%). The average number of missed days due to ankle sprains was 11.2 days. Most injuries were managed with rest, and only one male athlete underwent surgery due to an ankle sprain sustained during dancing. During the one-year follow-up, the incidence of ankle sprains, incidence rate per 1000 exposure hours, and recurrence rate of ankle sprains were 46.6% (male, 41.2%; female, 48.8%), 0.65 ankle sprains/1000 h, and 35.3%, respectively. No sex-related differences were observed. It is crucial to focus on the occurrence of ankle sprains and CAI in dancesport athletes with high heels. Future research should clarify the impact of ankle sprains on dancesport performance and develop preventive measures to reduce the incidence and recurrence of these associated injuries.

BACKGROUND: Agonist-antagonist muscle superset (SS) and paired-set (PS) strength training protocols enable the completion of training activities within a shorter period of time than traditional set. The purpose of this study was to investigate the effects of PS and SS through total volume (TV), set volume (SV), blood lactate concentration (LAC), rating of perceived exertion (RPE), and neuromuscular fatigue index (FInsm5). METHODS: Eleven males who train recreationally performed PS and SS consisting of bent-over row (BOR) and bench press (BP). In performing the PS, a single bout of BOR was followed by a rest interval of 60 seconds, the BP was then performed and followed by another rest interval of 60 seconds. When the SS was performed, a single bout of BOR and a single bout of BP were performed consecutively and followed by a single rest interval of 120 seconds. The exercise configurations were repeated until five sets were completed. The TV was calculated by multiplying the number of successful repetitions and the load. The LAC and RPE were measured at predetermined times. Electromyographic signals were recorded for use in the FInsm5 calculation. RESULTS: The RPE indicated that PS was significantly lower than SS (P<0.01). No significant differences between PS and SS were discovered in SV, TV, LAC, and FInsm5. CONCLUSIONS: This study demonstrates that PS has lower perceived exertion than SS when agonist-antagonist strength training protocols are selected as the training structure.

Fatigue is an inevitable part of resistance training, making its monitoring crucial to prevent performance decline. This study evaluated the validity of ratings of perceived exertion as a measure of fatigue during power bench press exercises. Fourteen sub-elite male athletes completed three bench press tasks with varying volumes (low, medium, and high) at 65% of their one-repetition maximum. The rating of perceived exertion, a spectral fatigue index, and velocity loss were measured across all conditions. Significant effects were observed for the overall ratings of perceived exertion, average velocity loss, and average spectral fatigue index (all p<0.001). As tasks progressed, the rating of perceived exertion and the spectral fatigue index increased significantly (p<0.001), while the velocity loss was not significant under the low-volume condition. Significant correlations were found between the rating of perceived exertion and the spectral fatigue index (r=0.547, p<0.001), the velocity loss and the spectral fatigue index (r=0.603, p<0.001), and the rating of perceived exertion and the velocity loss (r=0.667, p<0.001). The findings suggest that both the rating of perceived exertion and the velocity loss are valid measures of fatigue in power bench press exercises. However, the rating of perceived exertion is a more practical option due to its simplicity and accessibility. Furthermore, the rating of perceived exertion can act as a substitute for velocity when measurement tools are unavailable. It should be noted that velocity alone may not fully capture fatigue in low-repetition power training.