CHOOSING between two sports is hard enough, but try putting yourself in Kate McCarthy's shoes. 

The Brisbane Lions midfielder has represented Australia at touch football and track and field, and worn the maroon of Queensland in cricket.

But despite that, it was Australian football that stole her heart when two years ago she tried her luck at a training session with Yeronga in Brisbane's south.

"I went just to get more fitness and ended up loving the game," McCarthy said.

"I've given up everything else to play AFL. I love it – there's nothing like it."

It's a big statement coming from such a gifted sportswoman, and a big tick for the NAB AFL Women’s competition.

As a schoolgirl, McCarthy donned the green and gold at the Pan Pacific Youth Games on the back of her 100m personal best of 12.06 seconds.

She was also a long-time member of both the women's and mixed national touch footy teams, where her explosive speed was a major weapon.

But since switching codes, the 23-year-old has no doubts where her allegiances rest.

She said despite the obvious difference in physicality, and the need for sustained endurance, as opposed to repeated high-speed efforts, there were plenty of similarities between AFL and touch footy.

"It seems like such a different sport to touch, but reading the game is similar – looking for space and reading defences," she said.

"Once I got my head around the basics, I thought the two sports weren't that dissimilar.

"You get a lot more time in AFL as well. In touch you have to make a decision in half a second.

"I love getting the ball in space and having a run, and even running the other way to track down players. I love doing that in AFL."

Not surprisingly, the Lions plan on using McCarthy as an outside midfielder or winger, utilising her pace advantage.

She said her more experienced teammates had helped her flatten her kicking out over the past two years, and in a scary warning for opponents, the high school maths and PE teacher says she's now quicker than when she ran that 100m personal best as a junior. 

"I reckon with the strength training we do, I'd be quicker now," she said. 

McCarthy said she was genuinely thrilled to have a shot at excelling at another sport.

"I can't believe I've got this chance to play at the top level – I'm so excited."