11/09/2011 10:00 EST | Updated 01/09/2012 05:12 EST

Should Clocks Move Forward So Kids Can Play Outside Longer?


TORONTO - Now that clocks have been set back an hour in most parts of Canada and it's dark before dinnertime, a new British study on kids' physical activity might strike a chord with parents here.

A team led by Anna Goodman at the London School of Hygiene and Tropical Medicine tracked 325 children aged eight to 11 for a total of 817 days spread over four seasons.

They had the highest overall level of activity — mainly outdoor play — when there were 14 or more hours of daylight, and physical activity levels were significantly lower when there were fewer daylight hours. The effect remained the same even when bad weather was taken into account.

"It's been an argument made before that daylight saving, changing the clocks and having more daylight saving measures, should increase physical activity — I think this strengthens that argument," Goodman said in an interview from London.

"So I think it provides an extra plank in that kind of the support for (the) daylight savings bill as something which could be good for public health."

In Britain, a Daylight Savings Bill had second reading in the House of Commons last December. It proposes that clocks not be moved backward by an hour in October.

In Goodman's study, conducted with colleagues at University College London, the children wore accelerometers to record their body movements, and also kept a diary of their daily routines.

The accelerometers are a fancier version of step counters, she explained, and sit on the waist "so that if you move around or jump up or down or walk, or just shift in your chair a bit, they measure how much movement your body's doing."

"What we found was that on the long days, these were days with about 14 hours of daylight, children were more physically active specifically in the afternoon, so between 5 p.m. and 8 p.m.," Goodman said in a phone interview from London.

"There weren't differences earlier in the day, and it didn't seem to be explained by weather. And half of that effect — so half of the extra physical activity — seemed to be explained by the fact that children spend quite a bit more time playing outdoors on longer days."

The study was published Wednesday in the Journal of Physical Activity and Health.

Kelly Murumets, president and CEO of ParticipAction in Canada, said it's an interesting study, and she's not aware of similar work that's been done in Canada.

After school is a prime opportunity for kids to be active, she said.

"I think the study suggests ... that if it's light, kids would be more active or at least they'd be outdoors, and we know that if kids are outdoors, they'd be more physically active, that's for sure," she said.

"I think for me, the bottom line of this study is questioning policy changes, and whether we should be changing daylight savings time or not — that's probably for someone who's more of an expert in that area than me."

ParticipAction's main message to parents is to reduce sedentary time for their kids.

"We can limit computer time, we can limit gaming time, we can limit screen time in general. That's our job as a parent, and then provide options for the kids," she said.

Murumets suggested that if parents don't want their kids outdoors playing in the dark they could hold dance parties, or have other kids over for play dates.

"There are all kinds of games and activities that kids can be doing indoors even when it's dark during that 3 to 6 p.m. period," she said.

She said only seven per cent of Canadian children meet daily physical activity guidelines.

But she noted there are great resources in Canada that may not exist to the same extent in the United Kingdom.

She cited places like the YMCA that will offer subsidies for families if they're having difficulties with costs, community centres and local boys and girls clubs.

"In Canada I think community organizations are really committed to helping parents solve that problem for their own kids in that after-school time period," she said.

"It's not all doom and gloom. There is hope out there."