HOUSTON, Texas (KTRK) -- If you ever doubted your abilities to compete in the Ironman triathlon, we're sure you're not the only one.
Jeff Scace, a Green Beret who proudly served in Afghanistan, lost his fingertips to frostbite during a mission to honor fallen soldiers.
Doctors told him that his disability would hold him back, and he would never be able to compete in an Ironman.
But after training at the Memorial Hermann IRONMAN Sports Medicine Institute, Scace is now ready to compete in his first Ironman.
"They said I'd never be able to hold my children or climb a rope. The list went on and on and on," Scace said. "I've just been trying to knock those things off my list, one by one."
There's also Jeff Cottrell. Just five years ago, he weighed 500 pounds.
Cottrell could barely move around until he and his wife started working out together.
Since then, he has lost 220 pounds and has completed multiple marathons.
"I started walking five minutes at a time. I could only walk five minutes on the treadmill, and then I would sit down for five minutes," Cottrell explained. "That built up to 30 minutes, then 1-hour, then I started running."