MONTREAL—It’s not often you find a cross-fit athlete, but it is becoming more and more popular. Lara Stefanatos is quickly becoming one of the best at a very young age.

For most of us the question is quite simple: what is a cross-fit athlete?

“Cross-fit is a functional program. It's varied exercise at high intensity. What we do is more work over time,” said Mike Deboever of Reebok Cross-fit YUL.

It's certainly not for everyone, but Stefanatos was playing competitive tennis and was trying to get in better shape but couldn't find anything she liked.

“I always found going for runs kind of boring so I decided to try it and give it a shot and that was a year and a half ago and I haven't stopped since,” said Stefanatos.

It's a combination of several disciplines, including Olympic lifting, gymnastics and metabolic conditioning like running, rowing, skipping and swimming. Short workouts, high intensity.

“It's fun because it is always someone who pushes you beyond what you think that you can do and what you expect from yourself,” said Stefanatos.

She started doing it with her dad and before long her mom and sister joined in. They say that training at the Reebok Cross-fit YUL is addictive.

“It’s the intensity, the variety of the workout because you never know what you are going to get. It's the community and the spirit of the people in the gym,” said Lara’s dad, Gerry Stefanatos.

Stefanatos is only 16 and often competes against women who are 25. Her coach feels she has the drive and the motivation to compete in the cross-fit games in a few years.