Music in spinning classes: not always music for your ears!

World Hearing Day

So today is World Hearing Day, held to raise awareness on how to prevent deafness and hearing loss and promote ear and hearing care across the world^[1]. I would say a good way to start is creating and designing cardio classes (like spinning) that are healthy for the entire human body, including our hearing!

Music or amplified sound is present in our everyday life. As we listen, we're constantly anticipating the harmonies, melodies, and rhythms of songs and that influence our emotions and senses. Listening to our favourite song can make us happy, it can enhance the movie we are watching in the cinema or give us a boost while working out in a spinning class. Mostly it makes us feel good but it can also be dangerous. Our hearing is very sensitive. If you listen to loud music for too long it can lead to hearing damage.

Spinning classes: an exhausting hearing exercise

Every week I try to go to my health club to do some exercises. But this week, I decided to pump it up a little more and try something else: spinning, also known as indoor cycling. And, I have to say, it was an exhausting experience. But not only for my body also for my ears. I was shocked about how loud the music was and how much the instructor was doing her best to shout in the microphone of her headset to make sure everyone could follow.

I was measuring the noise levels with some Decibel Apps on my smartphone and came to an average of 92 decibels. A spinning class is available in almost every sports facility, fitness centre or gym.

• A session typically lasts 50-60 minutes and is led by an instructor who guides everyone accompanied by uplifting music.
• Spinning is a cardiovascular activity that helps reduce the risk of heart attack, high cholesterol, high blood pressure and, increase lung capacity^[2][3].
• Health authorities recommend 150 minutes of cardio exercise per week to reduce health risks^[4].

But what about hearing damage? It all depends on how long you are exposed to a certain noise level. With the 92 dB, I measured, it was still safe for me within a maximum exposure for about 1,5 hours^[4]. So, apparently, I was lucky, considering that a research from the United States found out a maximum of 116,7dB among 17 random spinning classes! Moreover, an average of 32 minutes was spent at >100 dB^[5]. Knowing that the maximum exposure time for 100dB is 15 minutes^[5], we can conclude that every participant in these spinning classes had some kind of hearing damage like noise-induced hearing loss (NIHL). NIHL is the second most common cause of permanent hearing impairment after age-related hearing loss^[6].

The instructors have even higher chances of getting hearing impairment. Research shows, in fact, that instructors teaching two or more high-intensity classes per day are at risk of hearing damage^[7]. Unfortunately, for this group of training professionals, the health risks are not solely related to the hearing system. Raising their voice to be understood by all people in the room, shouting even because of the excessively loud music can cause serious vocal damages.

Ask your inner ear  

Why does the music have to be so loud that it is damaging our hearing and affecting our wellbeing? Can we not just lower the volume, wear earplugs or improve the acoustics of the room? The answer is not that simple because of the fact that we just “like” loud music. Apparently we should blame our sacculus. A team led by psychologist Neil Todd, from the University of Manchester, has discovered that the sacculus, as a part of our inner ear, releases endorphins when stimulated by loud music. The sacculus, for instance,  particularly likes low frequencies musical beats (bass) above 90 decibels^[9] Another research was done by the Department of Speech Pathology and Audiology, at the University of the Witwatersrand in Johannesburg^[10] shows us which noise level we like the most when doing fitness exercises. Here are some outcomes about music volumes in the gym:

• 80 dB: too soft (52%) less enjoyable (38%)
• 85 dB: comfortable (75%) enjoyable (66%)
• 90 dB: comfortable (74%) enjoyable (76%)
• 95 dB: too loud (33%) enjoyable (57%)

So a difference of 5 decibels has a huge impact. It doesn’t sound that much, but it is clearly noticeable.

How to reduce the sound levels?

Reducing the sound levels can be easily achieved by adding sound-absorbing materials in the room. Mostly the materials being used in a spinning room are hard, flat and smooth surfaces like the mirrors on the wall or the concrete ceiling or floor which only reflects all the sound waves. by improving the room acoustics by reducing the reverberation time you lower the sound levels and also enhance the speech intelligibility of the instructor. In the Netherlands, they have a clear guideline which is called “Guidelines Accessibility Indoor sports accommodations”^[11] with a chapter only dedicated to fitness, aerobics, indoor cycling, and martial arts rooms (chapter 5.3 page 52). Regarding the room acoustics, the guideline states that the average reverberation time should be 0,60-0,80 seconds (125Hz-4000Hz) They are still guidelines but it’s a start.

References

_{^[1]  Wilson WJ, Herbstein N, The Role of Music Intensity in Aerobics: Implications for Hearing Conservation, Journal of the American Academy of Audiology, volume 14, Number 1, 2003}

_{^[2]  Nystoriak MA, Bhatnagar A. Cardiovascular Effects and Benefits of Exercise. Front Cardiovasc Med. 2018;5:135. Published 2018 Sep 28. doi:10.3389/fcvm.2018.00135}

_{^[3]  Jang-Gun Yoon, Seok-Hee Kim, Hyun-Seung Rhyu. Effects of 16-week spinning and bicycle exercise on body composition, physical fitness and blood variables of middle school students. Journal of Exercise Rehabilitation 2017;13(4):400-404}

_{^[4]  Piercy KL, Troiano RP, Ballard RM, et al. The Physical Activity Guidelines for Americans. JAMA. 2018;320(19):2020-2028. doi:10.1001/jama.2018.14854}

_{^[5]  Noise Exposure - Permissible Level and Duration.} 

_{^[6]  Sinha et al., Cycling Exercise Classes May Be Bad for Your (Hearing), The Laryngoscope. The American Laryngological, Rhinological and Otological Society Inc., August 2017}

_{^[7]  Taneja MK. Noise-induced hearing loss. Indian Journal of Otology, volume 20, issue 4, October 2014}

_{^[8] Petri AE, New York Times, Loud Fitness Classes Take a Toll on Instructors’ Voices, Jan.9 2020.} 

_{^[9]  Todd N, Evidence for a behavioral significance of saccular acoustic sensitivity in humans. The Journal of the Acoustical Society of America 110, 380 (2001)}

_{^[10] World Health Organization: Prevention of Blindness and Deafness (PBD).}

_{^[11]  Stichting Onbeperkt Sportief (2015). Richtlijnen toegankelijkheid indoor sportaccommodaties.}