These days a jog around the local park for Justin resident Ryan McDonald isn't as exhausting as it used to be.
"I didn't know how to use food properly and I enjoyed it," McDonald said.
Growing up, McDonald simply loved food -- at times overindulging on his family's home cooking and fast food.
"I was just sick and tired of being non-functioning," he said.
When McDonald topped out at a whopping 530 pounds on the scale, he came face-to-face with reality.
"I wanted to make a change and it wasn't kind of an ‘Ah-ha’ moment, it was kind of taking small steps," he said.
However, he didn’t use any fad diet or gastric bypass surgery. McDonald used exercise and a healthy diet.
Along with the support of his wife Jessica and his two children, McDonald’s hard work paid off.
In just two and half years he lost 300 pounds.
"It's so much fun to go to places that haven't seen him in a while. They're like, 'Where's Ryan?' I'm like, 'He's right here,'” his wife, Jessica McDonald, said.
McDonald is now pushing it to the next level by participating in the first “Mayor's Triathlon” in Fort Worth on Sunday.
McDonald first powered through a 300 meter pool swim, then a 15-mile bike ride through a hilly course and topped it off with a 3.1 mile run through downtown Fort Worth.
Even though McDonald viewed this triathlon as a challenge -- he is set to raise the bar for himself higher later this year.
In November, he'll participate in the Baja 1000 race, a desert ATV race in Mexico's Baja peninsula.
Unlike reality shows, McDonald isn't aiming for a cash prize. Instead he is raising money for the YMCA of Metropolitan Fort Worth to fight childhood obesity.
"It's great that the Y can be at the table to help get kids healthier through sports programs, swim lessons, just through active play," Derek Smith, the director of operations at the Fort Worth YMCA said.
McDonald crossed the triathlon finish line in 1:37:03.02.
For him, it's not just another race under his belt.
"It was not only a challenge and something I wanted to do -- but I can prove I can get out of the rut," he said.