Tracey Yukich collapsed from heat stroke on a California beach during her first Biggest Loser challenge one year ago.
After being airlifted to a nearby hospital, she woke up without her memory.
"I couldn't remember my birthday," she said. "I couldn't remember my name, didn't know I was married. I didn't remember any of that."
After two weeks in the hospital, Yukich made up her mind to get healthy, and a fierce competitor emerged.
Controversial decisions gave her an advantage in the game, but put her on the outs with her teammates.
When she finally returned home last August she realized she was the show's villain.
"It surprised us only because I knew a different side than what was being portrayed on national television," said friend Deborah Puskarich.
Yukich said all the controversy fueled her workouts.
"It really got me stronger, because I realized, 'It's OK.' It's all right because it's about me now," she said.
By the show's finale, she was down 118 pounds.
Today, running a mile is no challenge at all. In fact, she just finished the Boston Marathon.
"I'm going to be honest -- when I hit mile 17, I'm thinking, 'What in the world have I gotten myself into?'" Yukich said.
"It was an amazing day," she said
Her husband, Nick, said the girl he met in North Carolina reemerged in all the weight loss.
"It's good to see her self-esteem back up where it was," he said.
Now, Yukich said she's not only a a better mom and wife, but a person who is truly fit to inspire others.
She said she stays busy today raising her four children, giving motivational speeches and leading fitness boot camps.