Learning how to build active cities worldwide
It is not a new idea that cities can be designed to make it easier--or harder--for people to be physically active. This has been a topic of study for more than 15 years. Designing active cities is recommended by the World Health Organization and the US Surgeon General. However, most studies have been conducted in single countries, mainly in North America, Europe, and Australasia. We were concerned that each country has a limited range of environments, which may lead to underestimating the role of built environments in physical activity. It is unclear whether findings from one country can be applied to other countries, because every study used different methods. The International Physical Activity and Environment Network (IPEN) Adult Study was designed as a more definitive study of the importance of the design of cities for physical activity and health internationally.
On April 1, 2016 a major report from IPEN was released online by The Lancet, the world's most influential medical journal. The main finding was that adults from 10 countries who lived in the most "activity-friendly" neighborhoods did up to 90 minutes more physical activity than those who lived in the least "activity-friendly" neighborhoods. This amounts to about 60% of the recommended 150 minutes per week of physical activity. The relation of city design to physical activity was much stronger in this international study than in prior studies conducted in single countries. The findings were similar across countries. Thus, it appears that designing to cities to be "activity-friendly" is a globally-applicable solution to the pandemics of inactivity and non-communicable diseases such as heart disease, stroke, diabetes, and some cancers.
About the study
This study is special because it was conducted in 14 cities in 10 countries on 5 continents, with countries including Belgium, Brazil, Colombia, Czech Republic, Denmark, China (Hong Kong), Mexico, New Zealand, the UK, and the USA. The measures were objective, with environment measures assessed from government records using geographic information system (GIS) mapping software, and physical activity assessed with electronic accelerometers worn on the waist. The use of objective measures provides more confidence in the findings. Investigators in each country collected data using similar procedures so results would be comparable across countries. Over 6800 adults were included in the analyses.
Designing an active city
People were most active when their neighborhoods were densely populated, had several parks nearby, had good access to public transport, and had highly connected streets that provide direct routes from place to place. These principles of active cities applied across the 14 highly diverse cities. Some cities, such as Hong Kong and Aarhus, Denmark were especially well designed to encourage active transportation. Other cities, such as those in New Zealand had many parks, which helped people be active for recreation.
These results identify several aspects of the design and management of cities that can be altered to increase physical activity and reduce risk of obesity and non-communicable diseases. Implementing these changes will require the collaboration of health professionals with diverse sectors of government and society, including city planning, transportation, parks and recreation, and real estate development. Health professionals have a responsibility to become informed advocates for creating healthier environments. Ensuring cities are designed to be "activity-friendly" should now be considered an international health priority.
More lessons from IPEN
IPEN was begun in 2004 by James Sallis (US), Neville Owen (Australia), Ilse de Bourdeaudhuij (Belgium), and Jacqueline Kerr (US and UK). We invited investigators to join a collaborative international study and follow common procedures. Studies of adults were conducted in 12 countries, with most countries funded from internal sources, and international coordination funded by the National Cancer Institute of the US National Institutes of Health. I want to thank all the investigators for their collaborative spirit and the numerous funders for making the studies possible.
Publications based on IPEN Adult have been published on the relation of built environments to walking for recreation, walking and bicycling for transportation, and obesity, as well as other topics. More papers are coming. An IPEN Adolescent study is ongoing in 13 countries, and results will be forthcoming in the next year or so. The methods used in IPEN are available, and we encourage investigators and health agencies to use these measures so results can be compared. Our goal is to provide evidence that can be used to create more activity-friendly cities and improve health worldwide.
Download the paper and research brief
- The article in The Lancet is freely available here.
- A research brief summarizing the main results in a 2 page, easy-to-read format is available here.
- Read the press release.
Join the conversation
Join the conversation on Twitter using #GlobalActiveCities.
James F Sallis, PhD
Department of Family Medicine and Public Health
University of California, San Diego, USA