Now Varey is the national 50km running champion, set to represent Australia for the first time at December's long distance world championships in Doha, Qatar.

A part-time fresh food co-ordinator at Harrison Primary School, Varey also began running to set the example of a healthy lifestyle for her children, aged 14 and 12. But after running her first marathon last year, Varey wanted more for herself, too.

She took out this year's national title in her first 50km run during The Canberra Times Running Festival in April, then backed up only three weeks later to take out the Australian event in the international Wings for Life World Run.

The unique event involves a mass start, with runners eliminated when they're caught by a chase car that accelerates every hour.

More than 100,000 runners took part in the event worldwide at 35 locations, with Varey recording an Australian-best 51km before getting caught. The international winner was Japan's Yuko Watanabe, with 56.3km.

"It's a weird feeling, the finish line's chasing you," Varey said. "My legs were well and truly dead, but as soon as I saw the chase car coming I just got this power to keep running.

"It's really hard to pace yourself because you don't know where the finish line is."

Varey was raised in Canberra but moved to Western Australia for work with the navy, before returning home in 2011 as a mother of two.

"I became a mum and I let myself go a little bit," Varey said.

"I wanted to be a healthier person for my children so I decided to change my lifestyle. I wanted my kids to see that if you put your mind to something you can really do it."

"When I came back to Canberra, I realised it was too cold to go for walks, so I decided to start running. Now there's no stopping me, I'm known as the crazy running lady."

She clocks up to 180km a week, but Varey refuses to let running interfere with family life.

"I usually do my training run before they get out of bed, I'm walking back through the door at about 7am so I can get school lunches ready.