This editorial published in the British Journal of Sports Medicine in March 2011 summarises the health benefits and risks of cycling, and describes current controversies and evidence challenges for cycling policy and promotion.

The bicycle is a means for individual health-promoting behaviour, is a clinical tool for rehabilitation and a societal tool for contributing to a healthier environment.
Until recently there has been promising yet limited evidence on cycling-specific health benefits. A new systematic review identified 16 studies focusing on cycling-specific health outcomes. The studies identified a consistent positive relationship between cycling and cardiorespiratory fitness and functional benefits in boys and girls. Furthermore, they demonstrated improvements in cardiorespiratory fitness and disease risk factor profiles. Several longitudinal epidemiological studies have shown a significant risk reduction for all-cause and cancer mortality and for cardiovascular disease, colon and breast cancer, and obesity morbidity in middle-aged and older men and women.
There are also cycling-associated risks, especially traumatic injuries (requiring acute clinical treatment) and non-traumatic injuries. Next are the potential risks of exposure to poor air quality among cycle commuters. However, a recent analysis has compared the risks and benefits, and estimated that the life expectancy gained as a result of increased physical activity was many times larger (3–14 months gained) than the lost life expectancy due to increased air pollution (0.8–40 days lost) and increased traffic accidents (5–9days lost), when shifting from a car to cycle commuting in urban settings.