Teens and tweens living in sprawling Canadian cities are more likely to walk and bike than their peers living in more compact downtown areas, a new report finds.

Wednesday's report from Statistics Canada looked at urban sprawl and its relationship with active transportation, physical activity and obesity among Canadians aged 12 to 19.

"Something that was really interesting from it was that urban sprawl was associated with increases in active transportation among 12- to 15-year-olds, and by active transportation, I mean things like walking to get around, or cycling or rollerblading to travel from place to place," said study author Laura Seliske of Toronto, where she mainly uses public transit and walks to get around.

Seliske was interested in studying how our built environments can make it easier or harder to make healthier decisions, such as getting enough physical activity, for her doctoral thesis at Queen's University in Kingston.

Overall among 12- to 19-year-olds:

  • One in four said they expended energy to get around for at least 30 minutes a day.
  • One in three met guidelines for moderate-to-vigorous physical activity like playing sports, weightlifting or taking an aerobics class.
  • One in four of those who reported their height and weight were overweight or obese, likely an underestimate.

Urban sprawl was tied with active transportation and moderate to vigorous physical activity among young people.

Transport for kids versus adults

But the trend for young people ran counter to what has been reported for adults, a difference that Seliske said initially surprised her.

For adults, urban sprawl developments over a large geographic area can make it harder to walk or cycle between destinations, leading to more time stuck behind the wheel in traffic and less physical activity.

"Cycling in a subdivision, young people might be more comfortable with that versus cycling downtown in a more compact area, whereas [for] adults, driving through a subdivision is not a very efficient way to get around," Seliske said.

Young people are also more likely to play road hockey or basketball in a suburban cul-de-sac than downtown.

When the numbers were crunched taking Toronto, Vancouver and Montreal out of the picture, the statistical associations no longer held. That suggests it's youth in those big cities that are driving the relationships rather than those living in smaller cities, Seliske said.

Concerns about traffic and crime tend to discourage active transportation among young people. Those dissuading factors weren't measured consistently for everyone in this study.

"I think it's a balance between letting young people be physically active versus concerns for their safety," Seliske said. "I definitely see both sides."

The study included an index of urban sprawl that considered population density, what proportion of residents lived in the urban core and the extent of single family dwellings compared with condos and apartments. 

Researchers weren't able to tell if each participant had a driver's licence and access to a vehicle.

The study was based on the 2007-08 Canadian Community Health Survey of 7,017 people aged 12 to 19 in 33 census metropolitan areas, where two-thirds of the population lives.

With files from CBC's Amina Zafar