MADISON, Wis. -- The Ironman Wisconsin begins next Sunday at 7 a.m. in Lake Monona with a 2.4 mile swim.

Even before the starting pistol is fired, athletes will already be at work, treading water waiting for the signal to begin the race.

Among the crowd of some 2,400 participants, will be 12 tackling the ultimate physical test with an additional challenge: diabetes.

Participants like Aaron Perry who has been insulin dependent for 15 years, not only have to focus on the athletic essentials, but must stop to check their blood sugar many times along the way.

The group is competing as part of the Triabetes Project. Doctors have been tracking athletes' progress -- and their blood sugar -- as they train, and documentary film crews have been following them most of the way.

"Knowing more about diabetes this time around is definitely going to be a bonus for me," Perry told WISC-TV. "It was really neat this time around to interact with other diabetics, you learn some of the things they've done to be successful."

Perry completed Ironman Wisconsin in 2005, in about 16 hours. He's hoping to best that time this coming Sunday, but the real reason he's competing is far bigger than the numbers of the stopwatch.

"There are so many people, particularly within the African American community that are struggling with diabetes, and that's what I've tried to do is through my actions of competing and speaking to different organizations is just to inspire people to give themselves a fighting chance until a cure is discovered," said Perry. "Living with diabetes, I have absolutely no idea what this disease will do to my body in the years to come. And unless there is a cure, diabetes may take my life, but before I let that happen I will do all I can to control my diabetes."