Five-hundred feet above the English countryside, Melody Kearns stood on the grassy crown of Glastonbury Tor.

Her tour group had walked to the summit, step by strenuous step, climbing a path once tread by ancient pagans and Christian pilgrims. In every direction, Kearns could see patchwork farmland, emerald-green fields and bushy hedgerows.

A medieval tower, the last ruins of St. Michael's Church, guarded the mountain's peak.

"It was pretty profound. You could see everything," said Kearns, 55, a resident of Coeur d'Alene. "It was so beautiful. It was like you went back in time."

Eight months before the hike, in September 2009, Kearns wasn't ready for the Glastonbury Tor. Her physical fitness had slipped; extra pounds were weighing her down. She decided it was time for serious change - not just a crash diet or a new exercise routine, but true, life-altering change.

"I wanted to be able to fit on the airplane seat," she said. "I wanted to be able to climb up that big mountain."

At Peak Health and Wellness in Coeur d'Alene, Kearns signed up for The Biggest Loser Challenge, a weight loss and fitness program modeled after the TV reality show. She had participated in the eight-week Challenge before, but had regressed in the offseason.

This time around, Kearns was determined to make the most of her experience.

"You have to get our of your comfort zone in order to see changes," she said. "(The Challenge) gives you a way to be accountable. A platform for accountability."

Kearns joined the Red Team and formed a strong bond with her teammates. She pumped iron and increased her endurance. She tested herself in group fitness classes. Peak ran two more Biggest Loser seasons in the spring; Kearns joined those, too.

That summer, lighter, stronger and fitter, she enjoyed a comfortable plane ride, toured southern England and climbed her mountain.

"I'm just very thankful. I think it's a wonderful program," Kearns said. "It's worked for me, and I think it can work for a lot of people."

But she's not finished - the Biggest Loser Challenge is now in its fifth season, and Kearns is still on the Red Team. She's lost 40 pounds altogether, and her waistline is getting smaller all the time.

The Challenge has become one of Coeur d'Alene's most popular fitness programs. Seven teams and 140 Losers - as they're affectionately known - are participating this spring, led by Peak trainers Lindsay Herbert, Dana Davis, Chris Fox, Bryan Janzen, Megan Kane, Cheryl Gomez and Stuart Wagner.

"Trainers put their heart and soul into this thing for eight weeks," said Herbert, Red Team captain and Peak's fitness director. "It's just so rewarding to work with the people and see the changes they go through, physically and mentally."

Participants are expected to work hard. They complete assignments at the gym, cycling on exercise bikes, lifting weights, attending group classes. And every week, the trainers organize a grueling Last Chance Workout for their whole squad.

A point system keeps track of weight lost, inches dropped and body fat reduced. Individuals who lose the most pounds, the Biggest Losers, receive a prize at season's end. There's team awards, too.

"It's been the most successful thing I've ever done, as far as losing weight, feeling good, and building up strength and endurance," said Doreen Porter of Post Falls, a member of the Yellow Team. "And all of the trainers are so wonderful. You can talk to them about anything."

Porter is another Biggest Loser success story. Over the course of five Challenges, the 48-year-old has dropped 50 pounds. Before she joined the program, Porter couldn't jump rope or jog. Now she's taking on Peak's toughest classes, like body combat and spinning.

"I was the last person to ever finish anything in our workouts, and I'm not that one anymore," she said. "The thought doesn't occur to me that I can't meet my goals. Now it's 'How long is it gonna take to get there?'"

Her trainer is Yellow Team headman Chris Fox.

"He's exactly what I need," Porter said. "I need somebody to push myself to where I want to be. I don't want to let him down."

About 95 percent of the people who join the Challenge complete the program, Herbert said. Some folks have cut 15 percent of their body fat, or cinched their waistlines by 20 inches.

Many participants continue their workout regimens after Biggest Loser concludes.

To steer their Losers in a healthier direction, the team trainers stress nutrition and regular exercise. Extreme dieting is not part of their program.

"We really try to focus on a lifestyle change. What's going to happen when Biggest Loser is over?'" Herbert said. "Food is not the enemy. Food is fuel, and it can really make you feel good."

Twice every season, all of the Biggest Losers gather for a Team Challenge. The locations vary.

Earlier this month, the teams competed at Lake City High School, where trainers set up relay races and an arduous track workout. Challenge points were on the line, as usual.

In April the Losers will assemble once again, this time at Tubbs Hill. The challenge - a sweat-filled journey to the hill's highest point - will not be easy. But they'll draw strength from one another, from their hard-charging trainers, and they'll run up Tubbs and get it done.

These Losers have come too far to quit.

"I'm never going back," Porter said. "I say at times I'd like to be a happy fat person. Not gonna happen. I'm a lifer. Biggest Loser lifer."