Debbie Nicholson

"Smart growth" neighborhoods show a 46% increase of physical activity in kids

Physical inactivity is a leading cause of death and disease globally. According to WHO, physical inactivity kills more than three million people annually. Research suggests physical inactivity might be linked to community designs that discourage active living. A smart growth community contains features likely to promote active living (walkability, green space, mixed land use), but objective evidence on the potential benefits of smart growth communities is limited, according to the study.

Dr. Michael Jerrett, PhD, Associate Professor, School of Public Health, University of California, Berkeley, Division of Biostatistics, Department of Preventive Medicine, University of Southern California and lead author of this study along with colleagues examined whether living in a smart growth community was associated with an increased neighborhood centered leisure-time physical activity in children.

For the study 368 children aged 8 to 14 years who recently moved to the Preserve, a newly developed smart growth community near Chino, California. Families from eight conventional communities that were within a 30 minute drive from the Preserve were recruited for the comparison group and were matched to the intervention families on ethnicity and income. A family unit was defined as at least one parent and one child between grades three and eight. The study ran from March 2009 to March 2010 and the analysis was conducted in 2012.

The children wore small accelerometers and global positioning system (GPS) devices to measure their activity levels and determine how much activity occurred outside the home but within the neighborhood. The devices collected and recorded information about their physical activity for seven days and determined that living in a smart growth community would add 10 minutes of activity for each child each day.

The findings suggested that those children who lived in the smart growth community were linked to an increase of 46% physical activity in comparison to the control group.

The analysis evaluated the relationship between community type and total MVPA; moderate-vigorous physical activity (inside and outside the neighborhood) and found that total MVPA showed no difference between community design groups.

The analysis also showed that a child’s average daily minutes of total leisure time MVPA was slightly larger for the smart growth community at 28.7 in comparison to the control group at 26.33.

According to Dr. Jerrett "Ten minutes of extra activity a day may not sound like much, but it adds up. Taking in as little as 15 calories more than you expend on a daily basis can lead to weight gain over time, he noted. A child who weighs 100 pounds might burn an extra 30 calories in those 10 extra minutes of physical activity each day. "The basic idea is that even small things count.”

Past research research has found that only 42 percent of children aged 6 to11 get the recommended amount of physical activity. This drops to 8 percent for those aged 12 to 19 year Jarrett said. In fact, younger children in the smart growth community were 62 percent more active in their neighborhood than older children. Boys were 42 percent more active in the smart neighborhood than girls, Jerrett said.

In their conclusion the team writes “Part of the solution involves retrofitting existing cities by increasing density, livability, and transit opportunities within existing urban centers and limiting land conversion at the urban edge to conserve farmland and habitat. That said, green field suburban developments will still likely occur to meet the demands for affordable housing for a growing population. The findings of the current study suggest that such developments, if they adhere to smart growth planning principles, may promote increased leisure-time physical activity in children with concomitant reductions in the myriad health and environ- mental risks posed by auto dependency and sedentary.”

Kaid Benfield, director of sustainable communities at the Natural Resources Defense Council in Washington, D.C., founder of LEED for Neighborhood Development and a founder of Smart Growth America commented the conclusions of the study are very consistent with current thinking and research. Smart communities are being planned and created, but existing communities can be retrofitted to be smarter and encourage more exercise, he reported.

"The best way to retrofit suburbs is to redevelop parcels of land that become available as strip malls, big-box shopping, and regional malls go out of service -- replacing them with more walkable, mixed-use development."

This study appears in in the American Journal of Preventive Medicine.