Despite an "incredibly difficult and exhausting" day for Vernon's Shanda Hill, the ultra athlete is more than 57 kilometres into the final leg of her Ultra Deca triathlon.

Hill has completed the 38 km swim and 1,800 km bike ride, with 'just' 365 km of running left in the Brazil Ultra Tri Deca race. She is the sole woman competing.

According to her partner, Jacs Spence, Hill had just an hour and half of sleep before she completed the biking portion of the race on Wednesday, her fifth straight day of racing.

"What I witnessed yesterday was an athlete pushing herself past the point where most would quit," said Spence. "You could see it on her face. She wasn鈥檛 really with us anymore at that stage. She wasn鈥檛 fighting the bike. She wasn鈥檛 navigating corners. She wasn鈥檛 racing a triathlon. She was in a battle with her mind. And she won."

Spence added that the pain felt by Hill after the 1,800 km cycling was so intense that she collapsed at the side of the course with just two laps left.

"She hit a wall so hard that her only options were to quit or make even the slightest change to help her move forward."

This is Hill's first event since becoming the first and only woman to complete the inaugural South Africa Deca at the end of March.