Every parent has heard it. But for the Clarke family of Thornton, it's not just tolerated, but actively encouraged.

Siblings Madison, 13, and Casey Clarke, 10, are martial arts fighters - their favourite Jiu Jitsu, and also Judo - and can't get enough of training and competition.

"They both have natural talent, but their dedication is something else," their father Steven said. "They train twice every day for Jiu Jitsu and twice a week for judo."

For the uninitiated, judo involves mainly throwing techniques, while jiu jitsu is more centred on wrestling and on-ground techniques. Add the two together and, in theory at least, you have all bases covered.

It would seem to be a winning formula. The two only started fighting in competitions this year but already the accolades - and the medals - are starting to roll in.

Madison won a silver medal in this year's nationals, and a gold in the Pan Pacific titles. For Casey it was gold in the nationals, and bronze in the Pan Pacifics.

"They will get up and train together for 90 minutes every morning and again in at night night, and if there's a competition coming up they might train twice a night," Steven says. "They love it."

He puts their love of the sport down to a trip to the US where Madison saw Ronda Rousey competing in Judo.

"She was inspired by it and came back and wanted to fight, and Casey just picked it up too."

The two kids are home schooled which gives added flexibility to their day. Their club is Guerrilla Jiu Jitsu at Mayfield, their Judo at Tuggerah, so for Steven it means a lot of kilometres in the car each week.

"It can get up to about 1000 a week, especially when the nationals are on which are in Sydney," he said.

"I think for the next four or five Sundays we'll be in Sydney for competitions."

Madison said she loves the training side of things.

"It helps you prepare for anything that can happen in life," she said. "The competition is fun too. For me the Pan Pacifics were the best."

Steve said the family is lucky to have sponsors to help defray the costs - Hyperfly supply their equipment and subsidise entry into competitions, while Guerrilla JJ cover training costs.

"If anyone is interested in sponsoring, or maybe help out with overseas travel, it would be a great help."