Dan Fietsam feels he’s already run a marathon, of sorts, by helping to create 40 commercials for Sears, Roebuck over the last year. But because the creative director at Young & Rubicam is looking for more challenges, Fietsam will participate in his first triathlon on Aug. 4.

The Harbor Lights Triathlon in Waukegan, Ill., consists of an 800-meter swim, 21-kilometer bicycle ride and a six-kilometer run. The 37-year-old has been training all summer along Chicago’s lakefront. Like many first-time triathletes, he’sconfident in his running and biking, but said, “I’m a little nervous about the swimming.”

An avid runner, Fietsam said he was “getting bored” with just running. “I wanted a challenge, to do something different,” he said.

Fietsam isn’t just testing his athleticism. Proceeds from entry fees go to the St. Jude Children’s Research Hospital in Waukegan.

His possible follow-up—”If all goes well” on Sunday—is the Chicago Mrs. T’s Triathlon at the end of the month.

Fietsam, however, has no aspirations to enter an “Ironman” triathlon, the sport’s ultimate contest. “Being in the advertising business, you don’t have the time to train for something like that,” Fietsam said.