At the age of just 16, Mary Corbyn has earned the ring-name 'Scary Mary' after winning the World Kickboxing Championships four times.

This autumn the teenager will travel from Redcar to Russia to defend her world title where she hopes once again to bring back gold.

Outside the ring she's described as quiet and shy, but inside she's anything but the shrinking violet:

I went one day and I really enjoyed it so I told my mam that I wanted to carry it on, she didn't believe I did, so then I just still go. ''It's just all the energy. It helps me through it, it just feels amazing. As soon as the first round goes, it's alright after that.'' >

Mary Corbyn

Mary's many titles include Double British Open Champion, European Champion and four times World Gold Medalist.

Her family say they have seen kickboxing transform their shy girl:

She just disappeared when she was seven, everyone was out looking for her and she came home and said 'Oh I've joined kickboxing' and then she's never missed a session since, ever. Not one.'' >

Leasa Corbyn
'Scary Mary' has already won big in a number of competitions. Credit: ITV News

Mary's proud mum Leasa is backing her all of the way:

Before she goes into the ring she doesn't speak to you, she doesn't look at you, she won't talk to anybody but then when she's in the ring, she's a totally different kid. ''It's just as if she's in the zone. She's just our champ, always will be.'' >

Chloe Willis, Mary's sister

Mary is now preparing to defend her world title in this year's championships in September. Her coach Catilin Chapman is also a former champion, so she's got more than a fighting chance:

She'll go further than I did, without a doubt. She'll come back the same. she'll come back with numerous gold medals and walk back in here and start training again on the Monday.''

Caitlin Chapman, Coach

Mary's plan to bring back gold in September is to work hard and stay focused:

Really focus, like everything around you can't hear of see so like, in the zone.''

Mary Corbyn