He's used to the competion looking at his back while he's running competitively, but he always put swimming on the backburner.
In his second year running in the River Cities Triathlon in Benton, LA, he learned from his mistake.
"Running's my strength," Zderic said. "I had a weak swim my first year. I missed the biker's and I got gapped. I'm more of a stronger runner."
The Baton Rouge native's been competing in triathlons more than two decades. He knows winning's as much about strategy as it is speed. He's always been able to outlast runners and hang with the pack on the bike, but it took an injury in college to hone his swimming skills.
"I got a stress fracture. The coach told me to do water running, and I got frustrated with doing water running for six weeks, going back and forth in a pool running when I saw people swimming. I just started swimming. I had friends doing triathlons back then and I've been hooked ever since."
The River Cities Triathon is a sprint triathlon. Olympic triathlons take 2 to 3 hours. Ironman triathonscan take up to 16 hours.
"That's nuts! It's like doing a job all-day long. It's like doing a shift."
His wife's competing in an ironman competition. He says the pressure's on to keep pace with her.
"I keep resisting, but I know the pressure's mounting. If my wife gets a certain time in October, I told her I'd do one next year. I want her to do well, but I kinda don't want her to do well."