Colin Hole emerged from Lake Michigan on Saturday morning, cool air hitting his wet skin, and kept going. The 9-year-old Winnetka resident was one of roughly 700 children who competed in the youth triathlon at Supertri Chicago, the two-day lakefront endurance event at Foster Beach that organizers say is on track to become the world's largest triathlon.

Hole and his friend Shaw Weinberg, also 9 and from Winnetka, both raced in the 7-to-10 age group, which started at 7 a.m. Saturday, Aug. 22. Their course: a 100-meter swim in the shallow water off Foster Beach, a bike ride of just over 2 miles along lakefront roads and a run of a little over half a mile.

"I like to not think about beating everyone else, but about beating myself," Hole told the Chicago Tribune. "My goal is just to get at least a minute faster."

The toughest stretch, he said, comes right after the swim, when the cool morning air makes it hard to warm up. Then comes the worry about cramping during the run.

Weinberg had skipped the competition the previous year and worried she might be out of practice. She took a few breaks during the run but still crossed the finish line ahead of more than half the kids in her age group.

She plans to return next year.

The youth race kicked off a two-day event formerly known as the Chicago Triathlon. More than 9,000 participants were expected across the full weekend, with adult sprint, Olympic and relay races scheduled for Sunday, Aug. 23, at Monroe Harbor. Michael D'Hulst, founder and CEO of Supertri, told Yahoo Sports that Chicago's identity as a sports city fuels the event's growth.

The event's corporate fundraising challenge has raised $18 million cumulatively for the Center for Cancer and Blood Disorders at Ann & Robert H. Lurie Children's Hospital of Chicago, according to Supertri's website. The corporate challenge brought in more than $84,000 for pediatric cancer and blood disorder research in a prior year, according to the Tribune; the 2026 goal is $125,000. Supertri Chicago also generated $17.5 million in economic impact for the city last year, according to ABC 7.

About 40% of the event's 8,000-plus participants are competing in a triathlon for the first time. For Hole and Weinberg, the draw is beating their own times.