It’s 5:30 a.m. and a 16-year-old Bob Harper makes his bed and heads out into the soft dawn light. For the next 10 hours, he herds cattle and works tirelessly to manage the farm he grew up on.

Fast-forward to 2004 and he’s walking onto the set of The Biggest Loser — he’d just secured the job that would turn him into a household name. It was a job that was unlike any he’d had before, but on that very first day of work, he knew that it was going to be special.

Harper moved to Los Angeles from Nashville, Tennessee in 1992 to pursue a spark of interest in fitness that grew into an all-encompassing passion.

In Nashville, he lived right next to an exercise studio and was inspired by the people coming in—then leaving drenched in sweat but smiling. To satisfy his curiosity, he went in to discover the source of their happiness. “My eyes opened up in a completely different way,” he says. “Seeing a group of people coming together and doing fitness was super exciting.”

Soon afterward he packed up his little car and drove across the country to “the capital of fitness,” Los Angeles, California. “I bet on myself,” he says. “That was the scariest thing that I've ever done in my life—just leaving friends, family, everything I knew to move to a place where I had no idea what I was getting myself into.” At that point, he wasn’t dreaming of the Hollywood scene and being in front of the camera. “It was not anything that interested me,” he says. “People that come to Los Angeles, they always have the idea of being an actor, an artist in some way, a writer—and I wanted to be in fitness. That’s all I wanted.”

Specifically, he wanted to be a personal trainer. “I took that word—personal—very seriously,” he says. “If you were coming to me ready to change your life, I was going all in too,” he explains, adding that in LA he started to notice a disconcerting trend. “It used to drive me crazy to see some trainers that were on their phones while their client was on the treadmill or just not being invested.” If you know Harper, you know that he’s going to give you 100 percent.

So how does a really good, really fulfilled personal trainer living in LA end up hosting what became the most popular fitness-based television show on the planet? Naturally, Harper had celebrity clients, and those clients saw something special in him - the “it” factor, which encompasses dynamism, passion, and outspokenness. “People said, you need to go in for this job,” he recalls. He had a healthy level of skepticism at first but when he found out that it was based solely on diet and exercise, he decided to audition.

The real challenge started after he got the part when he entered that house full of lights and cameras. “I had never worked with such overweight people,” he says. “I remember thinking I have got my work cut out for me.”

Luckily, he considers himself determined, fully committed, and focused. “One of the biggest things I learned from the celebrities that I worked with early on is that you have to put all your effort, all your time, all your energy into what you're doing right now,” he says. He moved in with a family friend that lived by the set of The Biggest Loser. “I gave up everything. I lost friends. I lost time. There was no going on vacations. There were no days off,” he says. “I believe that if you really want to be at the top of your game, then you've got to give up a lot, but then you really reap the benefits in so many other ways.”

The fame and success that he reaped from 18 seasons on the show (16 as a trainer and two as the host) would seem sufficiently worthwhile to many of us, but Harper hasn’t halted his mission to bring health and fitness into the homes of anyone and everyone willing to put in the work. Since The Biggest Loser, he’s spoken and led fitness classes all across the country and worked with Michelle Obama on her Let's Move initiative. More recently, he’s poured his passion and energy into traveling around the country speaking with fellow heart attack survivors. “That has been my greatest achievement because it was something that I suffered and recovered from,” he says.

What’s next? Getting you fitter than ever via NEOU with his Weight Loss Starter Pack. “In the world that we're living in now, at-home fitness is taking the driver's seat,” he says. “This is where fitness is right now. People aren't going to gyms. People aren't able to go to group fitness classes. NEOU is super interesting to me now more than ever because people are looking for this and people are needing this.”