An Idea To Run With

This field trip is really a track and field trip - the final lap in a marathon that began months ago.

Thousands of Los Angeles kids have been running, walking and jogging at school, tracking their progress and racking up a total of 26 miles, CBS News correspondent Sandra Hughes reports.

Kay Morris launched "Marathon Kids" in Austin, Texas. Students in a half-dozen cities are now up and running.

"We're not trying to build marathon runners," Morris said. "We're just trying to move children from sedentary to non-sedentary."

Elementary school students in Los Angeles haven't seen a gym teacher in more than a decade, and the district isn't even meeting minimum state requirements for physical education.

Regular classroom teachers try to keep kids moving, but it's an uphill battle, with one-third of the nation's kids considered overweight.

That's why Allesandro Elementary joined the running program. The kids are healthier - and the bonus: Academic performance is up significantly - 23 points on standardized tests.

According to several studies, cutting gym to make more time for academics does not boost grades.

"The brain research that's going on shows that when we move, it stimulates the brain and the chemicals are released that actually help us to learn," said L.A. Schools physical education director Chad Fenwick.

It's helped to build confidence in both Esparza sisters.

"Did you ever think you would be able to do something like that?" Hughes asked them.

"Yes," Valerie said.

"I thought I couldn't," Kelsey said.

"I feel like I'm doing great. I've been losing weight," said Andrew Lucero.

How much?

"Maybe, like, 30 pounds," he said.

This program works because kids like Andrew Lucero bring the lessons home.

"It's important for him to see that it's not just him - but we're actually doing it together," said Andrew's mother, Marcella Lucero.

Marathon Kids has more than 100,000 children running with that idea nationwide.