PHILADELPHIA (CBS) — Sarah Reinertsen is used to pushing through pain with the right leg she was born with, and the left one, that was made just for her.

“I lost my leg at the age of 7 at NYU Hospital,” said Reinertsen. “I had a tissue disease as a child that effected the growth of my limb”

The 36-year-old was part of the 7th annual Philadelphia Triathlon on Sunday which includes biking, swimming and running. As part of a relay team Sarah biked a 25 mile course.

“Even when it hurts and you’re going up a hill I always make sure to smile,” joked Reinertsen after the race.  “It tricks the body into thinking it’s not so bad at least for the moment.”

Her path down perseverance road, has been pretty impressive. In 2005 she became the first woman with a prosthetic leg to finish the Ironman competition. In 2006 she competed on the CBS show, “The Amazing Race.”

“I have to say the amazing race is 20 billion times harder than any triathlon I’ve ever done,” said  Reinertsen.

This Orange County California resident motivated her teammates and her coaches from the Challenged Athletes Foundation, which provides training and equipment to disabled athletes.

“She’s just amazing,” said coach Tim Maguire. “A true inspiration of a true athlete.”

“One of the things I really learned from the Amazing Race, is a new mantra in my life…fear less live more,”  Reinertsen declared.

Reported by Jericka Duncan, CBS 3.