Most high school students in Nova Scotia fail to get the bare minimum of exercise needed to be healthy, according to the first fitness study of its kind in Canada.

Researchers used an electronic device to track young people's physical activity level in the province, which has the second highest rate of obesity in the country.

Activity levels of 1,700 randomly selected students were measured using an accelerometer, a small device on a belt that attaches to the hip underneath clothing. The device records the intensity, frequency and time of day of the students' movements.

Schools will be asked to incorporate physical activity into classes

Unlike other studies on children's health, the method didn't rely on anecdotal evidence, but on physical data. It's considered the most comprehensive and accurate study done to date.

"Questionnaires don't provide accurate data by and large," said Prof. Roy Rasmussen of Saint Francis Xavier University in Antigonish . "If you ask the children for example in Grade 3, their recall of what they've done isn't as reliable as we'd like."

The study looked at Grade 3, Grade 7 and Grade 11 students.

Researchers found elementary school students were the most active, but 40 per cent were either overweight, or at risk of being overweight. Only 10 per cent of 16-year-olds meet national standards of exercise.

Sedentary teens could cost health care system more in future

"The most disturbing trend is that only eight per cent of boys and five per cent of the girls are getting enough activity for health benefits," said Dr. Phil Campagna, who teaches human kinetics at Dalhousie University in Halifax.

A better habit than watching TV

Researchers are using the data to make recommendations on how to get children more active.

Campagna said he wants to see compulsory physical education continue right up until Grade 12. But many high school students said they're discouraged from taking gym because it means they'll have to give up an academic subject.

He added phys ed teachers are well trained and want to make a difference, but their hands are tied.

They fear sedentary youth will become unhealthy adults, leading to increased health problems and costs.

"What we're seeing right now is our children being less active. They're going to probably be inactive adults, and that's going to drive our health-care costs even higher."

Nova Scotia's Education Department has a pilot project in eight schools to develop a plan to improve the province's physical education levels. The province recommends high school students should get 30 minutes of exercise a day.

But Campagna said parents shouldn't wait for the schools to change. "Get the kids to turn off the TV and the Internet."