Context: Sound levels in fitness classes often exceed safe levels despite studies that show many participants find high sound levels stressful.
Aims: The objective is to determine if lower sound levels in spinning classes significantly impact exercise intensity and to determine if class participants prefer the music played at lower levels.
Settings and design: Observational study of 1-hour group spin classes.
Methods and materials: Sound levels were measured in 18 spin classes over two weeks. No adjustments were made in week-1 and sound levels were decreased by 3 dB in week-2. Participant preferences and data on post-class hearing changes were collected via post-class questionnaires (n = 213) and divided into three terciles based on the total sound exposure of corresponding classes.
Statistical analysis used: Unweighted survey generalized linear models are used to sort the causal relationships between different variables simultaneously and participant responses. The Chi-square test is used to reveal statistically significant relationships between two or more categorical variables.
Results: When mean sound levels exceeded 98.4 dBC, respondents were 23 times more likely to report the music as too loud than too quiet (P < 0.05), and four times more likely to prefer a decrease, rather than an increase, in sound level (P < 0.05). There was no significant difference in respondents reporting high exercise intensity between the middle (95.7-98.1 dBC) and upper (98.4-101.0 dBC) terciles, 67.1% and 71.8%, respectively (P = 0.53). Overall, 25.9% of respondents reported auditory symptoms following classes. Analysis in the context of dBA and dBC produced congruent conclusions and interpretations.
Conclusions: Sound levels in many fitness classes remain dangerously high. However, music level can be lowered without a significant impact on perceived exercise intensity and many participants prefer lower sound levels than current levels.
Keywords: Exercise intensity; fitness class; music level; noise exposure; noise-induced hearing loss; recreational noise exposure; sound level.