Two-and-a-half years ago, registered nurse Catherine Malette could not even do a pull-up, let alone an obstacle course challenge like those made popular by the TV show American Ninja Warrior.

Today, she breezes through gruelling hurdles such as running up a warped wall four metres high, and can conquer unpredictable obstacle challenges that require strength and agility, and puts balance, co-ordination, grip endurance and upper-body power to the test.

Later this month, Malette is set to compete against the top ninja athletes from around the world at the UNAA World Series Championship Finals.

“When you look at the obstacles, at first you're always amazed, like I could never do that, and you then just go, and you can do it,” said Malette.

Her training began with bouldering -- a type of rock climbing that is usually closer to the ground and does not typically use ropes or harnesses -- and fell in love with the sport.

Then six months ago, she signed up for her first ninja competition and won.

The adrenaline rush from that experience had Malette hooked, and she is now setting her sights on capturing a world title when she competes in Prior Lake, Minnesota.

But it is not as easy as it looks, she said.

“Your throat burns, you're exhausted, your shoulder burns, you're tired, and you just need to keep going,” she said. “It's really hard mentally. That's what I'm really working on right now.”