Abstract
IMPORTANCE: Loud music in group fitness classes is often believed to enhance motivation and performance but poses a risk for noise-induced hearing loss. OBJECTIVE: To assess whether lower music volume during fitness classes results in comparable perceived exertion compared with higher music levels and to explore hearing protection behaviors among participants. DESIGN, SETTING, AND PARTICIPANTS: This comparative effectiveness study using a partially repeated measures design surveyed group fitness class attendees from February 1 to 28, 2025, at a fitness studio in Los Angeles, California, regarding perceived exercise intensity, music loudness, and hearing protection behaviors. EXPOSURES: Participants attended 1-hour group fitness classes under typical (louder) and reduced music volume conditions (≥3-dBA reduction). MAIN OUTCOMES AND MEASURES: Perceived exertion was compared between louder and quieter class conditions using multivariable mixed-effects linear regression to account for repeated measurements from participants. A noninferiority framework was applied, with noninferiority defined as the lower bound of the 97.5% CI. RESULTS: A total of 189 participants completed 239 surveys, and 21 participants contributed surveys in both sound conditions. The median (range) age was 28 (17-59) years, and 165 (87.3%) were female. The mean sound levels were 91.4 dBA (95% CI, 91.1-91.9 dBA) for louder classes (n = 122) and 88.5 dBA (95% CI, 88.0-88.9 dBA) for quieter classes (n = 117). The lower bound of the 97.5% CI for the difference in perceived exertion (Borg CR-10) between louder and quieter classes (β = -0.66; 97.5% CI, -1.09 to -0.22) did not exceed the CI for the noninferiority threshold of -1.5, indicating noninferiority in perceived exertion in quieter classes compared to louder classes. Continuous unit-based modeling of sound intensity confirmed noninferiority for decrements up to 4 dBA. Twenty-eight individuals (14.8%) reported ever experiencing postclass tinnitus, and 4 participants (2.1%) reported consistently using hearing protection during classes. CONCLUSIONS AND RELEVANCE: In this comparative effectiveness study, reducing music volume in group fitness classes did not lead to meaningful reductions in perceived exertion and may reduce the risk of noise-induced hearing loss. These findings support implementing safer sound practices in fitness environments and underscore the need for increased awareness and education on hearing protection.