Many girls who are active in sports during elementary school find themselves dropping out by high school, deciding they’re just not good enough to play anymore.

But a group called FitSpirit, with the help of spokesperson Sophie Grégoire Trudeau, is trying to change that, to show girls all the great benefit in staying active.

As someone who battled an eating disorder in her younger years, Grégoire Trudeau told CTV’s Your Morning she knows how hard the teen years can be on a girl’s self-esteem.

“In the teen years, we go through tough times, and sometimes we let go of the physical activities and that’s what happening with one out of two Canadian girls between 12 and 17,” she said Monday from Montreal.

She says many girls find themselves with little energy after they abandon sports, so they turn to caffeine, or they turn to smoking or alcohol to try to boost their confidence, setting them on the road to poorer health.

“It becomes a huge cost not only to girls but to society as a whole,” Grégoire Trudeau said.

But getting girls to become active again forces them to push their own limits, both physically and mentally.

“So it’s a great tool to be able to get to know yourself in a culture that, most of the time, tries to impose cultural standards on us,” she said.

FitSpirit’s goal is to teach teenage girls that being active doesn’t have to mean joining a team or being competitive against one another. It can mean simply having fun being active with friends.

“It just means doing something you enjoy doing. This is what FitSpirit is about. It’s about a non-competitive, empathetic, compassionate atmosphere in which girls get together to practice sports,” she said.

Every year, FitSpirit organizes running events, bringing together thousands of teenage girls to challenge them to run a 5K or 10K race. The group will be hosting a run in Montreal this week, Quebec City next week, and Toronto later in May.

Grégoire Trudeau says, by showing girls how they can challenge themselves, they can learn how “to fall in love with their bodies,” how to push themselves, and how to build up their own self-esteem.

“They can learn to become their own mentors, their own teachers,” she said. “We have to encourage them, as parents, to believe in themselves. That’s the great lesson.”