KNOXVILLE, Tenn. — For weeks, runners have trained their bodies for endurance and speed. But one Alcoa woman is using a different approach to prepare for the 5K race of the Covenant Health Knoxville Marathon. She's changing her diet.

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Runner Carrie Ridenour and her son Lucas have been training side-by-side to prepare for the 5K on Sunday.

"I look forward to running,” Ridenour said. “The other day I went and bought new running shoes, and I was so excited."

Looking at her now, it's hard to believe this milestone achievement was nearly impossible for her almost a year ago.

"I couldn't get bend over and tie my shoes without getting out of breath."

The extra weight weighed on her health, and even strained the way she viewed herself.

"I got out of being active. That's probably where I put my weight on," Ridenour said.  "I was to the point where I didn't want to look at myself. So I thought I've got to do something about this."

Ridenour decided to train for the Covenant Health Knoxville Marathon’s 5K. She ran the race last year to lose weight, but was unsuccessful. This, year she changed her strategy.

"That's when I decided to start eating Keto," said Ridenour.

A Ketogenic Diet, or Keto Diet, is a low-carb, high-fat weight loss program, similar to the Adkins Diet. In the program, salmon, eggs, and meat are welcomed foods. But dieters avoid starches, grains and sugary foods.

"And immediately, I saw results and felt better. And here I am, 80 pounds later."

Now, Ridenour believes she has the tools to go the distance -both in the 5K race on Sunday and for the rest of her life.

"I can't imagine going back to the way I was before."