Karen, Shayla and Tristan Carrigan train twice a week with the Lake Macquarie PCYC Judo Club.

They also own a fish and chip shop at Waratah, which must be manned seven days a week.

But somehow, they manage to juggle both.

Shayla, 13, started judo three years ago.

She won bronze at her first competition when she was 11.

A year later Shayla claimed her first gold medal at the state championships in Blacktown.

Her brother Tristan, 10, wasn't far behind her, claiming silver in his age division.

Tristan also holds a gold medal from the Central Coast regional championships, which he entered last year.

Mrs Carrigan initially enrolled Shayla in the self defense sport because she wanted peace of mind.

"I like the thought that if she goes walking down the street she's going to be safe because she knows how to defend herself," Mrs Carrigan said.

Tristan followed in his sister's footsteps because he wanted to have a bit of fun.

The sport has also proved beneficial for Tristan's autism.

Mrs Carrigan joined her children a year ago for fitness and has since caught up to Tristan on yellow belt.

"It was good doing a sport where I could join in and not watch from the sidelines as you would with something like soccer.

"Having the business, we couldn't commit to a weekend sport, so we thought judo was great because we could train on weeknights."

Last month Mrs Carrigan and Shayla travelled to Hobart to compete in the national championships. It was Mrs Carrigan's first competition.

The pair walked away with bronze in the kime-no-kata pattern, where they both competed against experienced black belts.

Shayla, who has her orange belt, was also crowned the 2014 national champion in her weight and age division.

Their next competition is at Blacktown on November 22.