ID=7067069Sunday morning, thousands of people will step up to the start line on Clinch Avenue, ready to run mile after mile through the city of Knoxville.

Perry Pruitt will join the crowd of racers this year at the Covenant Health Knoxville race.

"I'm doing the half marathon, and just to complete it will be huge… so as long as I can still walk when I cross the finish line I'll be happy," Pruitt joked.

Just a few months ago, that goal seemed almost too great to achieve, back when Pruitt still weighed more than 350 pounds.

Part of it was just life," he explained about the decade-long weight gain. "When I was in high school I played football and I had a couple knee injuries and that's when I first started gaining some weight. Then when I got out of high school I lost some of it so I could get into the military, but then they still declined me because of my knee injuries, and I kind of gave up at that point."

His weight and poor fitness became a problem, especially when it came to his job. Pruitt serves as a firefighter on the Karns Volunteer Squad.

"The number one killer for line-of-duty deaths of firefighters is cardiac arrest," Pruitt said. "Mostly because they're not in proper physical condition."

He decided it was time to get into shape. Pruitt tried unsuccessfully to score one of the coveted spots on NBC's famous show, the Biggest Loser. However, he knew an alum of the NBC show who had another team in mind for Pruitt.

"Joe Mitchell [Biggest Loser, Season 12] told me about the Covenant Health Biggest Winner thing and I was like, sure! I mean what do I have to lose? So I jumped on it and they let me be on the team" he said.

He started the intense workout and nutrition regimen last fall at Fort Sanders Health and Fitness Center, and soon learned how much he enjoyed working out.

"I'm running, walking, doing spin class… everything I can do at Fort Sanders, cross fit…" he listed, explaining the lifestyle change. "On my days off I used to lay around and watch TV, and that's what I liked to do at that time. Now I don't hardly watch any TV. I'd rather be working out or running or just doing something and it's become fun again."

Pruitt lost nearly 90 pounds since he started his journey. He's shaved several minutes off his average mile time, and even more inches off his middle.

He's also formed lasting friendships with fellow members of the Covenant Health Biggest Winner team.

"Everybody says stuff to encourage you and that's just been awesome," he said.

Pruitt continues to fight fires, but he'd like to get certified to teach one of his new passions, too: spin class.

He wants others to achieve the kind of success he found on the Biggest Winner team, and hopes to inspire them to try.

"Now I have the attitude of: 'I can, I will, I am,'" he said. "If you don't ever start and don't ever try, then you can't do anything."