ince the golden days of aerobics, when leotards,
legwarmers and headbands were the height of fitness
fashion, music has been an integral feature of group
exercise. Back then classes were loud – both the music and the
fashion! In today’s group exercise studios the fashion has quietened
down, but the music remains as loud as ever.
Along with my team from the National Acoustic Laboratories, I
teamed up with the University of Newcastle to compare noise levels
in today’s fitness classes (2009-2011) with those recorded over
a decade earlier (1997-1998). In total, we measured noise levels in
100 fitness classes in Newcastle and Sydney. We found that while
noise levels in low-intensity classes (like BODYBALANCE™ or
BODYPUMP™) have dropped slightly, noise levels in high-intensity
classes (like Spin or BODYCOMBAT™) are higher than ever, with an
average noise level of 93 decibels.
The graph in Figure 1, opposite, shows how the different class
types compare. The Spin/RPM™/Cycle class can be seen to be the
noisiest class type, with the noise level reaching as high as 99 dB –
about as loud as an average nightclub. Some participants we spoke
to came out of their Spin classes wearing earplugs – they loved the
workout but hated the noise!
So what do these findings mean – and what are the implications
for your health, safety, and ultimately your hearing? Australian
workplace health and safety laws stipulate that our noise exposure at
work must not exceed an average noise level of 85 dB over an 8-hour
period. With every 3-dB increase in noise level, the time period must
be halved. So while 85 is considered to be acceptable for eight
hours, 88 dB is only OK for four hours, and 91 for two hours, and
S
UP THE BEAT – NOT
THE VOLUME!
A comparative study shows that many
instructors are still cranking the volume in
classes up too high for safety.
WORDS: ELIZABETH BEACH
so on. For volumes of 94 dB (around the average of high-intensity
classes), the maximum daily dose is one hour. Exceeding this noise
dose increases your likelihood of sustaining hearing damage.
Let’s think about this from your point of view. You’r e a casual
fitness instructor teaching six 1-hour classes a week. On Mondays
and Tuesdays you teach a 1-hour class where the noise level is 94
dB. So far, so good. But on Wednesday, you teach four hour-long
classes. Remember, the allowable noise limit for four hours is 88
dB, but if the output from your sound system is at 94 dB, by the time
you have finished work for the day, you will have exceeded the daily
legal noise limit four times over. This has implications for you and
your employer – you may be damaging your hearing, and he or she
may be breaking the law.
Remember also that noise exposure is cumulative and teaching
26 | NETWORK SPRING 2014
The 30-second article
• A comparison of fitness classes from 2009-2011 with those from
1997-1998 found that noise levels remain too high in many classes
• Indoor cycle classes were the noisiest class type – with the
noise level reaching as high as 99 dB
• Exceeding recommended workplace volume levels increases your
likelihood of sustaining hearing damage – and may be unlawful
• Research from physiology labs suggests that increasing the
tempo, not the volume, is the best way to get your class moving.