Doctor fulfilling promise to join once-obese patient in triathlon

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A Houston-based doctor who hoped to encourage his patient made a pretty big promise but will he keep it? Let’s just say Dr. Garth Davis is now pumping up the tires on his bicycle, checking the laces on his running shoes, packing his swimming trunks and buying a plane ticket.   

Dr. Davis made a promise to his patient, Marcus Cook, and he plans to keep it on Saturday. 

“About a year ago, I promised Marcus if he was going to try a triathlon, I was going to do it with him and now this weekend, we're going to be doing a triathlon in Miami together,” smiles UT Physicians - Memorial Hermann Memorial City Hospital bariatric surgeon Dr. Davis. 

Cook stands at a height of 5-feet 8-inches tall and weighed almost 500 pounds.

“I stayed away from pictures because I didn't want to see that guy because I've always been successful in business,” explains Cook, but he says his 489-pound body made him feel like an unhealthy, abnormal failure. “I had to become the funny guy instead of the normal guy that's not big.”

When Cook's colleague took a picture of him and posted it to social media, Cook couldn't believe what he was seeing. 

“And I was like uh, uh, that is not me,” says Cook, a father of four who had gastric bypass surgery in September. 

“What we do is we cut and divide the stomach, creating a smaller stomach so you feel full faster,” explains Dr. Davis.

“I want to be the one that walks my daughters down the aisle," says Cook. "I want to be the guy sitting in the sidelines watching my boys play football.”

“What I tell people is, ‘If you do what you've always done, you get what you've always gotten,’ and my goal is to have people try something different,” says Dr. Davis.

“When he said, ‘You have to do something new every day,’ I just said you know what, I'm going to do that,” says Cook. Living by that motto, Cook has lost 230 pounds. He says he went from spending his entire work day inside his truck to committing to walk every day.  

“I can remember walking the 20 minutes a day and it was like the hardest thing I've ever done in my life.” Then Cook graduated to riding a bicycle, running and training for a triathlon.

“And I started to run with my son and it was the first time I'd ever ran with my son and he was 16 years old,” says a teary-eyed Cook.

“I've never had someone get quite the success that Marcus has then join them on a race," adds Dr. Davis. "So this will be something new for me.”

Cook says lap band surgery did not work for him in 2008 and after that surgery, that one sentence Dr. Davis said to him to "do something new every day" has changed his life and he hopes his story will encourage others to commit to getting healthy.  Cook is now exercising, eating right and he'll take part in his first triathlon with his doctor right by his side.

“There's someone out there, there's someone just like me that's watching," says Cook while crying. "They're thinking it's over and it's not over.”

To follow Cook's weight loss journey visit: