Activity-friendlier the neighbourhood, more the exercise

Washington: People, who live in activity-friendly neighbourhoods, take up to 90 minutes more exercise per week, a new study suggests.

With physical inactivity responsible for over 5 million deaths per year, the University of California authors say that creating healthier cities is an important part of the public health response to the global disease burden of physical inactivity.

The study included 6822 adults aged 18-66 from 14 cities in 10 countries from the International Physical activity and Environment Network (IPEN). The cities or regions included were Ghent (Belgium), Curitiba (Brazil), Bogota (Colombia), Olomouc (Czech Republic), Aarhus (Denmark), Hong Kong (China), Cuernavaca (Mexico), North Shore, Waitakere, Wellington and Christchurch (New Zealand), Stoke-on-Trent (UK), Seattle and Baltimore (USA).

The research team mapped out the neighbourhood features from the areas around the participants' homes, such as residential density, number of street intersections, public transport stops, number of parks, mixed land use, and nearest public transport points. Physical activity was measured by using accelerometers worn around participants' waists for a minimum of four days, recording movement every minute.

On average, participants across all 14 cities did 37 minutes per day moderate to vigorous physical activity - equivalent to brisk walking or more. Baltimore had the lowest average rate of activity (29.2 min per day) and Wellington had the highest (50.1 min per day).

The four neighbourhood features which were most strongly associated with increased physical activity were high residential density, number of intersections, number of public transport stops, and number of parks within walking distance. The researchers controlled for factors including age, sex, education, marital and employment status and whether neighbourhoods were classed as high or low income. The activity-friendly characteristics applied across cities, suggesting they are important design principles that can be applied internationally.

The difference in physical activity between participants living in the most and least activity-friendly neighbourhoods ranged from 68-89 minutes per week, representing 45-59 percent of the recommended 150 minutes per week.

Lead author James Sallis explained that neighbourhoods with high residential density tend to have connected streets, shops and services meaning people will be more likely to walk to their local shops. Interestingly, distance to nearest transport stop was not associated with higher levels of physical activity, whereas the number of nearby transport stops was.

Sallis added that this might mean that with more options, people are more likely to walk further to get to a transport stop that best meets their needs. The number of local parks was also important since parks not only provide places for sport, but also a pleasant environment to walk in.

The study appears in The Lancet.