Key To Child Fitness Is Intensity, Not Duration
November 10, 2012

Intensity Of Exercise, Not Duration, Key To Fitness In Children

redOrbit Staff & Wire Reports — Your Universe Online

Children may need less than 10 minutes of taxing exercise per day to stay fit and healthy, but many of them aren't even getting that, a team of researchers from across Canada claim in a new study.

According to a statement, Richard Lewanczuk of the University of Alberta, Jonathan McGavock of the Manitoba Institute of Child Health, and colleagues recruited a total of more than 600 youngsters between the ages of 9 and 17.

Each of them were given monitors to track their physical activity levels over a period of seven days, and each of them had their weight, waist size, and blood pressure monitored on a regular basis.

After reviewing data collected through the Healthy Hearts program in the Black Gold Regional School system in Leduc and nearby communities south of Edmonton, the researchers discovered that nearly 70% of the subjects spent their time performing sedentary activities. Twenty-three percent of that time was spent in light physical activity, nearly 7% in moderate physical activity, and just 0.6% in vigorous physical activity.

"If you watch late-night television, or look in the backs of magazines, you'll see magical ads saying you need just 10 minutes a day or five minutes a day of exercise to stay fit. And for those of us in the medical field, we just rolled our eyes at that. But surprisingly, they may actually be right and that's what this research shows," Lewanczuk, co-principle investigator of the study, said in a statement.

"Our research showed children don't need a lot of intense physical activity to get the health benefits of exercise -- seven minutes or more of vigorous physical activity was all that was required," he added. "But the seven minutes had to be intense to prevent weight gain, obesity and its adverse health consequences. And most kids weren't getting that."

Lewanczuk and McGavock were joined by experts from the University of Manitoba, Queen's University, the University of Newcastle, as well as other University of Alberta researchers, during the course of the study.

Their findings, which were detailed in the journal Archives of Pediatrics & Adolescent Medicine, also found girls were more sedentary on average than boys, and the chances of being overweight decreased as the intensity of the exercise increased.

Furthermore, they did not find the anticipated health benefits from mild or moderate activity, even if the duration of that exercise increased. However, those kids who did participate in vigorous physical activity saw their health benefits rise significantly when they exercised for more than seven minutes at a time.

"This research tells us that a brisk walk isn't good enough," Lewanczuk said. "Kids have to get out and do a high-intensity activity in addition to maintaining a background of mild to moderate activity. There's a strong correlation between obesity, fitness and activity. Activity and fitness is linked to a reduction in obesity and good health outcomes."

"Getting young children to make vigorous physical activity part of their daily routines is important, especially considering activity levels in the teenage years drop right off," Lewanczuk says. "And previously published research from the same group of children shows kids are more active at school than they are at home," the University of Alberta said in its statement, adding that the researchers hope that their findings "will help schools decide what type of mandatory physical activity is needed."