TEMPE, Ariz. — It's early Sunday morning and hundreds of athletes are getting ready to start a swim in at Tempe Town Lake. 

But this isn't an ordinary swim - and these aren't your ordinary athletes.

This is the start of IRONMAN Arizona, which includes a 2.4 mile swim, a 112 mile bike ride and a full 26.2 mile marathon.

"She’s just like a lot of these other people," Walter Winkler says of his daughter Danielle. "They find this to be fun."

Winkler says he's traveled the world to watch his daughter compete, including a trip to Germany and recently Madison, Wisconsin.  

"It blows me away," Winkler says. "She started just doing a 5K."

But racing in Tempe brings back a lot of memories. He and his family used to live here.

"One of her childhood friends this morning was a volunteer on the kayaks," he explains. "So it comes full circle sometimes."

If you look down the road, you can see a big cardboard head popping out.

"This is Troy," explains Suzanne Peasley, showing off the big cardboard cutout of her brother Troy Witt.

"He saw me do it in 2014 and told me I was totally crazy and he would never get into this craziness and the next thing we knew two years later he was doing the race himself."

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Peasley says they would always see funny signs while watching other IRONMAN races and they though the humor might help her brother, too.

"We didn't show it to him before so when we saw it this morning he laughed and thought it was great."

There's an energy in the crowd as the athletes power by. Just watching is motivating and shows not only a test of ability, but a testament to the human spirit.

"It's about finding something deep inside yourself," Peasley says. "To just push through and finish. It's finding what you're made of."

The IRONMAN Arizona has been held in Tempe since 2005. For more information, click here.