Health benefits of cycling

Advantages for wellbeing outweight the risks

In 2005 the European Union outlined a vital area of action on chronic disease prevention: ‘addressing the obesogenic environment to stimulate physical activity.’ A key feature of an obesogenic environment is that it fosters low levels of physical activity, and urban areas are particular hotspots. Promoting walking and cycling as alternative forms of transport that are an alternative to sedentary options such as driving cars help to increase physical activity levels by making it part of daily life. However, in order to promote cycling for health reasons, the benefits to wellbeing need to outweigh the risks. Although there may be a benefit at societal level in the shift from private car use to cycling (e.g. reduced air pollution), is the shift disadvantageous to the cyclist?

On the one hand, while the cyclist may benefit from increased physical activity, on the other hand the activity may increase the pollutants inhaled due to increased breathing rate. Researchers in The Netherlands evaluated the risks and benefits for both the individual who shifts from car driving to cycling and for society as a whole. In the study, the relative risks comparing car driving and cycling were derived from a hypothetical scenario based upon statistics in The Netherlands. This is important to take into account because in The Netherlands there is extensive cycling infrastructure, including restrictions on car use through traffic calming in residential areas and car-free zones, that help to facilitate regular and safer cycling. The Netherlands also is one of the safest countries for fatal traffic accidents, particularly in comparison to other European countries such as France, the United Kingdom and Spain where the risk of a fatal traffic accident for cyclists is substantially higher.

The principal finding from the study was that for those who shift mode of transport, increased rates of physical activity due to cycling resulted in around a nine times greater gain in life years than would be lost in life years due to air pollution and traffic accidents. The benefits for the society as a whole due to reduced air pollution were greater still. The beneficial effect for cyclists is three to fourteen more months gained over and above the potential mortality effect from air pollution and increase in traffic accidents.

Would these benefits be translated to other cities? The researchers repeated the traffic accident calculations for the UK, where the risk of fatality is higher. However, the overall benefits of cycling were still seven times greater than the associated risks.

In terms of using this study for interventions that encourage physical activity, policies would need to be accompanied by efforts and measures to limit risk factors that would reduce the benefits of cycling. This could include careful infrastructural choices (e.g. not placing cycling lanes in close proximity to major roads to reduce inhalation of pollutants) and by managing car traffic through limitations or bans in certain areas. If concerned about the increasingly common obesogenic environments in which large proportions of populations live, urban planners and those working in policy related to the built environment should think carefully about how to integrate accessible and safe cycling infrastructure into cities.

Source: Environmental Health Perspectives, 30 June 2010.

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