David Iwaszko crossed the Chicago Marathon finish line in Grant Park on October 11, limping through knee pain that hit him at mile 14 but refusing to stop. The 55-year-old retired deputy police chief had transformed his health over four years, going from 307 pounds to roughly 165 to 170 pounds.
Before that finish line moment, Iwaszko spent 26 years in law enforcement, rising to deputy chief of the Calumet City Police Department before retiring in 2020, according to The Lansing Journal. The south suburban Cook County department he served polices roughly 36,500 residents with a force of about 91 sworn officers, per the Calumet City Police Department. Iwaszko is now a Bank of America vice president, according to the Chicago Tribune, which covered his completion of the 26.2-mile course.
A Four-Year Climb From 307 Pounds
Iwaszko weighed 307 pounds when he retired from policing in 2020, the Lansing Journal reports. He began walking and running and does a lot of cardio. He shed 140 pounds and, per the same account, no longer needed prescription medications for high blood pressure and diabetes.
He has said his family's medical history weighed heavily on his decision to change course. His father died at 51, an uncle died young, and his mother died of cancer in her 60s, according to the Lansing Journal. Becoming a grandfather sharpened that urgency, and he has said he wants his grandsons to grow up watching him adopt a don't-quit mindset.
Building Toward 26.2 Miles
Iwaszko didn't jump straight into marathon training. Over four years he worked up through local 5K and 10K races before tackling the Bank of America Chicago 13.1 half marathon this past June, the Lansing Journal notes. He once joked that he didn't like driving 26 miles, let alone running it, and has described running as a way to keep in shape.
The marathon itself tested that resolve. Pain in Iwaszko's right knee at mile 14 slowed him considerably. He chose to push through and finish rather than call for a ride. The course's official cutoff was six hours and 30 minutes, according to Wikipedia's entry on the event. Former Chicago Cub Anthony Rizzo finished the same race in 5 hours, 34 minutes and 54 seconds.
Running With More Than 55,000 Others
Iwaszko was one of more than 55,000 registered runners in the 48th Bank of America Chicago Marathon on October 11, the largest field in the race's history, according to Marathon Journal. The 2026 race drew more than 160,000 applicants through its registration lottery. Charity runners in the 2025 race raised a record $47.1 million for local and global nonprofits, an $11 million jump from the year before, per Bank of America.
From the Marathon to the Boxing Ring
Iwaszko isn't resting on his marathon finish. He was set to box in a charity event the following week.
