Children's physical activity starts declining at age 7, U.K. study indicates

Children may develop couch potato ways as early as age seven, contrary to the widely held view that it starts in adolescence, according to a study published in the British Journal of Sports Medicine .

Researchers in Glasgow and Newcastle in the U.K. sought to determine when physical activity levels start declining. The "Gateshead Millennium Cohort Study" also indicates that sedentary habits tend to develop in both boys and girls.  

For the research, 545 individuals provided physical activity data at two or more points in time. The children, from northeast England, were followed over an eight-year period, and the researchers measured their activity levels at ages seven, nine, 12 and 15.

The children wore an accelerometer during waking hours for seven days, and removed it to go to sleep or do water sports.

Activity declined in boys and girls

The study found physical activity declined steadily in both boys and girls over the eight years.

There was no sharp decline in activity levels in adolescence, said study author John Reilly, a professor from the University of Strathclyde. In fact, the decline in activity may begin as soon as the children enter school, before age seven, he said.

On average, girls spent 75 minutes a day in moderate or strenuous physical activity at age seven, but that fell to 41 minutes at age 15.

Boys spent an average of 75 minutes a day exercising at age seven and that fell to 51 minutes at age 15.

A significant minority of the boys — about 19 per cent — who were very active at age seven maintained the same level at age 15.

The study authors recommend that efforts to get children moving begin in childhood, be geared to both boys and girls, and include more physical activity in schools, an approach that is attracting attention in Canada.

This is increasingly important as children and youth are lured into sedentary activities in front of video-game and cellphone screens, the British Journal of Sports Medicine said.

What about Canadian kids?

Guidelines introduced in 2016 from Participaction, a Canadian initiative geared to encouraging physical activity, recommend children and youth be limited to no more than two hours of screen time daily.

The guidelines call for:

• 60 minutes a day of strenuous physical activity that raises the heart rate.
• Several hours of light physical activity.
• Nine to 11 hours of sleep for children aged five to 13 and eight to 10 hours for youth aged 14-17.
• Limited sitting for extended periods.

Participaction found only 14 per cent of Canadian children aged five to 11, and five per cent of those 12 to 17 get the recommended hour of strenuous physical activity every day.

The program recommended that parents provide their children with both scheduled activities, such as sports and dance, and free time to engage in active play, including outdoor play.

It also pointed to the 62 per cent of Canadian children and youth who are driven to school, suggesting parents encourage walking or riding a bike to school to build activity into the day.

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