Magical Number for Kids' Activity is 7

Seven minutes of daily physical activity is enough to reduce obesity risk in kids

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Kids run, climb, crawl and jump. But is that activity enough to stop them from becoming overweight or obese? Well, yes – if the activity is intense enough and lasts long enough.

A recent study found that just seven minutes of intense physical activity each day is all children need to lower their risk of obesity - just as long as the activity is vigorous enough.

Unsurprisingly, these researchers found that the children's weight, waist size and blood pressure decreased the more physical activity the children got – and the more intense that activity was.

"Encourage physical activity - for everyone."

The study, led by Jacqueline Hay, of the Manitoba Institute of Child Health and the Department of Pediatrics and Child Health at the University of Manitoba in Winnipeg, Canada, aimed to determine how physical activity relates to children's risk factors for cardiovascular or metabolic diseases.

The researchers used data from a 2008 study involving 605 youth aged 9 to 17. About a quarter (26 percent) of the participants were overweight or obese. The children and teens were given devices to wear for a week which monitored their daily physical activity.

Then the participants were assessed for their weight, their waist size, their blood pressure and their "cardiorespiratory fitness," which relates to how much oxygen they use.

The researchers did not find any noticeable differences in risk factors for cardiovascular or metabolic diseases among children who had light or moderate physical activity.

In fact, mild and moderate exercise did not seem to offer the kind of health benefits the researchers expected to find. What mattered was very vigorous physical activity.

And they found that the magic number to stave off being overweight or having a high blood pressure was seven. The researchers also found that the children who were overweight were unhealthier than those who were an appropriate weight.

This may seem obvious, but it calls into question some reason studies that claim a person can be overweight and still be healthy, the researchers said.

They also noted that children's activity during evenings and on the weekends was far lower than during the week or at school, so the children may be spending too much time in front of screens instead of being physically active.

But the most important finding was that children need vigorous exercise every day.

"This research tells us that a brisk walk isn't good enough," said senior author Richard Lewanczuk in a release about the study. "Kids have to get out and do a high-intensity activity in addition to maintaining a background of mild to moderate activity."

The study was published November 9 in the Archives of Pediatrics & Adolescent Medicine. The research was funded by grants from the Canadian Diabetes Association and the Alberta Center for the Child, Family and Community Research. Individual researchers were also supported by various fellowships and chairs. The other declared no conflicts of interest.

Reviewed by: 
Review Date: 
November 14, 2012
Last Updated:
November 16, 2012