People exercise less when they live next to noisy traffic
The likelihood of taking daily exercise falls by five per cent for every ten decibels of noise, shows new study.
A new study suggests that living close to loud traffic makes people less active.
The reason may be that the noise from traffic disturbs your sleep, which makes it harder to find the motivation to get up and exercise the next day.
“People who sleep poorly exercise less. Therefore it’s reasonable to think that the connection is that people who are exposed to a lot of traffic noise, sleep poorly at night and therefore don’t have energy to exercise. People may not know that their sleep isn’t optimal, but it might still affect them,” says co-author Nina Roswall, a postdoc from the Danish Cancer Society.
The scientists behind the study cannot rule out other possible reasons behind the connection between traffic noise and exercise habits. The options for exercise could also be poorer in the areas with more traffic as there may not be as many parks to go for a run.
Further studies are needed before they can narrow down the exact culprit, says Roswall.
The study is published in the International Journal of Hygiene and Environmental Health.
Activity level falls when noise increases
Noise from traffic in the streets of two of Denmark’s largest cities, Copenhagen and Aarhus, is usually somewhere between 40 and 70 decibels.
According to the new study, the probability that a person exercises daily falls by five per cent for every ten decibels of noise.
This means that someone who lives in an area where the traffic noise reaches 70 decibels is 15 per cent less likely to exercise daily than someone who lives in an area with 40 decibels of traffic noise.
“Physical inactivity is a big public health problem in general and we may have found one of the reasons as to why people don’t exercise enough,” says Roswall.
Stress and lack of sleep can affect exercise
According to Roswall, the connection between traffic noise and lack of exercise could be explained in one two ways, one of which is poor sleep.
“We can’t say anything for sure based on our study, but it’s reasonable to think that traffic noise disturbs sleep at night and that it can affect the desire to exercise,” she says.
Traffic noise can also lead to physical stress. According to Roswall, previous studies indicate that constant noise stresses the body and that this can lead to decreased physical activity.
“At the same time, lack of sleep and stress can lead to poor recovery in the body, and this can perhaps play a role in [our data],” says Roswall.
Previous studies have shown a clear connection between living with noisy traffic and the risk of developing heart disease. Other studies have also found a connection with cancer.
“We know that it’s harmful for our health to live in a place where there’s a lot of noise from road traffic. Our study is the latest evidence for this. One possible connection could be that disturbed sleep affects hormone production, which regulates appetite and hunger among other things. If we sleep poorly, we exercise less, and perhaps at the same time we eat more food and sweet dishes. Altogether it increases the risk of developing a whole range of diseases,” says Roswall.
Reduces occurrence of disease and diabetes
The new results are significant in terms of public health, says Mathias Ried-Larsen, group leader at the Center for Active Health at Rigshospitalet and the Danish Diabetes Academy.
Ried-Larsen was not involved in the new study, but he also studies how exercise influences the severity of type-2 diabetes.
“It’s very interesting to see what a difference traffic noise can make to people’s exercise habits. It’s very significant. Just imagine if you could move the entire population out of an area of high traffic noise. It will have a massive influence on, for example, incidences of type-2 diabetes and heart disease,” he says.
But we need more studies in order to identify the precise connection, he says.
“The question is always, whether people exercise less because they live on [a major street in a capital city] or whether [that street] attracts a particular type of person that generally exercises less. But it’s also plausible that the connection could be disturbed sleep as the study authors suggest,” says Ried-Larsen.
It is difficult to conclude whether people exercise less due to traffic noise, or that these busy areas simply have fewer options for exercise, he says.
Read more in the Danish version of this story on Videnskab.dk
Translated by: Catherine Jex
- 'Residential exposure to traffic noise and leisure-time sports – A population-based study', International Journal of Hygiene and Environmental Health (2017), doi: 10.1016/j.ijheh.2017.05.010