The athlete, who is now also a motivational speaker, took to Instagram this week to explain how self-conscious she feels following procedures she undertakes to improve her skin that was severely burnt in 2011 when she was caught in a bushfire while competing in an ultra marathon in The Kimberley, in far north Western Australia.

"I've been recovering from laser surgery for the past week. Sometimes I get really self-conscious after surgery - I feel like everyone is having a huge stickybeak at me," she said.

"This week I felt it big time, and yeah, it sucks. But you know what? Sometimes in life when you're on a quest to improve yourself, no one else's opinion or judgement matters. You've gotta own yourself and wear your challenges like a boss - after all, no one else is gonna do it for you!"

The post - a selfie - clocked up more than 12,000 likes in less than 24-hours. She was also inundated with messages of support.

Pitt is renowned for her mental, physical and emotional grit and competed in the Port Macquarie Ironman challenge last month. She cycled 180 kilometres, ran 42 kilometres and completed a 3.8 kilometre swim in just over 13 hours.

Shortly after that the 28-year-old travelled to Papua New Guinea and trekked Kokoda Track in eight days.

She also raised more than $400,000 for Interplast, an organisation that supports children with burns in developing countries.

Pitt is set to wed her long-time partner Michael Hoskin, who proposed last year after buying a diamond ring while she was in intensive care five years ago.

"She's beautiful, you know, she's amazing," he told The Australian Women's Weekly.