"By making me promise him that I would [get healthy,] he saved my life," Murburg tells PEOPLE of his late son

By Patrick Gomez
Updated October 18, 2014 02:05 PM
Trae Patton/NBC

After burying his son, Mike Murburg ballooned to almost 400 lbs. – but he also credits his son for saving his life and setting him down the path to healthier living.

“It really didn t get to me until I was about five minutes away from The National Cemetery,” the Biggest Loser contestant tells PEOPLE of realizing the role his son played in his weight-loss journey. “Then it occurred to me that by making me promise him that I would [get healthy], he saved my life.”

This realization caused Murburg – whose 20-year-old son Ehren died during Special Forces training in 2008 – to become especially emotional when visiting his son’s grave for the first time since becoming a contestant on the 16th season of the NBC reality weight-loss competition.

“It was difficult for me to get through the filming,” Murburg says of taping the segment, which aired Thursday night after he was eliminated.

But the former college wrestler and football player has now returned home to Darby, Florida, and is dedicated to continuing his weight loss despite any setbacks he faces.

“I ended up contracting an infection in my toe while I was on the ranch,” says Murburg, who also suffered a major knee injury while on the ranch. “So the first three weeks I was home, I had to be on antibiotics. I couldn t exercise in the pool anymore so I had to once again think of creative multiple body system integrations so I could keep up my workout. It’s just another challenge.”

One thing that hasn’t been a challenge for the attorney is finding time to maintain his social life in addition to his two-a-day workouts, which include swimming four miles and walking nine miles daily.

“Today, if you want to see me and socialize then we can get together at the gym. I’ve had a lot of friends fall into it and are working out when they weren t before. It’s healthier for everybody,” he says. “It has become a lifestyle. I’ve pretty much become addicted to it.”

But while Murburg hopes to continue to lose more than the 120 lbs. he has already shed, he also isn’t afraid to let himself enjoy the small pleasures in life.

“I’ll still have a glass of wine every once in a while,” he says. “I think I’ve maybe had four glasses since I’ve been back.”

The Biggest Loser airs Thursdays at 8 p.m. ET on NBC.

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