Don't stop riding because the air quality is bad, but if you can, ride away from main roads. That's the message of research from the University of Copenhagen which has found that the benefits of exercise outweigh the harmful effects of air pollution.
The study shows that despite its adverse effects on health, air pollution should not stop people from exercising in urban areas.
"Even for those living in the most polluted areas of Copenhagen, it is healthier to go for a run, a walk or to cycle to work than it is to stay inactive," says Associate Professor Zorana Jovanovic Andersen from the Centre for Epidemiology and Screening at the University of Copenhagen.
Professor Andersen says that physical activity reduces the risk of premature mortality, while air pollution increases it. But when we exercise we take in more airborne pollutants, and they accumulate in our lungs.
"Air pollution is often perceived as a barrier to exercise in urban areas. In the face of an increasing health burden due to rising physical inactivity and obesity in modern societies, our findings provide support for efforts in promoting exercise, even in urban areas with high pollution," says Professor Andersen.
"However, we would still advise people to exercise and cycle in green areas, parks, woods, with low air pollution and away from busy roads, when possible."
The study looked at data from 52,061 subjects, aged 50-65 years, from the two main cities Aarhus and Copenhagen, who participated in the cohort study Diet, Cancer and Health.
From 1993-97, they reported on their physical leisure activities, including sports, cycling to and from work, gardening and walking. The researchers then estimated air pollution levels from traffic at their residential addresses.
5,500 participants died before 2010, and the researchers observed about 20% fewer deaths among those who exercised than among those who didn't exercise, even for those who lived in the most polluted areas, in central Copenhagen and Aarhus, or close to busy roads and highways.
However, Andersen sounds a mote of warning that might make you think twice about doing laps of Oxford Street.
"It is also important to note that these results pertain to Denmark and sites with similar air pollution levels, and may not necessary be true in cities with several fold higher air pollution levels, as seen in other parts of the world," she says.
The research results have been published in the journal Environmental Health Perspectives.
John has been writing about bikes and cycling for over 30 years since discovering that people were mug enough to pay him for it rather than expecting him to do an honest day's work.
He was heavily involved in the mountain bike boom of the late 1980s as a racer, team manager and race promoter, and that led to writing for Mountain Biking UK magazine shortly after its inception. He got the gig by phoning up the editor and telling him the magazine was rubbish and he could do better. Rather than telling him to get lost, MBUK editor Tym Manley called John’s bluff and the rest is history.
Since then he has worked on MTB Pro magazine and was editor of Maximum Mountain Bike and Australian Mountain Bike magazines, before switching to the web in 2000 to work for CyclingNews.com. Along with road.cc founder Tony Farelly, John was on the launch team for BikeRadar.com and subsequently became editor in chief of Future Publishing’s group of cycling magazines and websites, including Cycling Plus, MBUK, What Mountain Bike and Procycling.
John has also written for Cyclist magazine, edited the BikeMagic website and was founding editor of TotalWomensCycling.com before handing over to someone far more representative of the site's main audience.
He joined road.cc in 2013. He lives in Cambridge where the lack of hills is more than made up for by the headwinds.