A new study shows the health benefits of cycling or walking around cities outweigh the harmful effects of air pollution.
Have you ever wondered whether the amount of exhaust fumes you suck in while cycling or walking to work counteracts the benefits of the exercise you're doing?
Regular exercise reduces the risk of obesity, diabetes and heart disease, however, there have been concerns about the potential health risks of air pollution while walking and cycling in city environments.
Air pollution contributes to early deaths. A UK study this year found it contributes to 40,000 early deaths a year. In Auckland it's responsible for around 300.
New research published in Preventive Medicine shows for an average air pollution concentration in an urban area, you would need to cycle for seven hours or walk for 16 hours before the risks would begin to outweigh the benefits.
Bike Auckland chair, Barbara Cuthbert, says there's 10 percent growth in cycling year on year.
"The fumes you'd get riding a bike in peak hour traffic are less than if you were a driver sitting in idle traffic because on a bike you're always moving, you bypass all the stopped traffic."
The average air pollution level for cities around the world is 22 micrograms per cubic metre, according to the World Health Organisation.
New Zealand falls well below -- in Auckland in 2012 air pollution was recorded at an average seven micrograms. Wellington recorded six micrograms but the highest level of air pollution was in Timaru at 13 micrograms.
That compares to London at 16 micrograms and Delhi, one of the most polluted cities in the world, had 153 micrograms.
The study also shows that if cycling replaces driving, the trade-off would be even more beneficial -- perhaps another reason to get out of your car and choose active travel to get to work.