Turns out, runners didn't actually run a half marathon in last weekend's HOKA Chicago Half Marathon.
Several runners started pointing out that their distance trackers were quite a bit short of the 13.1 miles to complete a half marathon, but still, they ran from the start line to the finish line.
"Everybody on my Strava got 12.64 miles. [Were] things a tad short today?" one runner commented on the event's Instagram page.
Other runners started replying to the message acknowledging similar distances.
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Organizers replied by saying the runners were in fact correct -- the race wasn't 13.1 miles.
"A required, last-minute course change was implemented due to unforeseen circumstances in partnership with the city of Chicago," a comment from the event's official account read. "The impact of this change was a reduction to the overall course distance. We apologize for any inconvenience as we chose to prioritize athlete safety."
Several runners expressed frustration over the lack of notification about the distance change and others requested refunds.
"You chose to keep athletes in the dark and hope no one noticed. We paid for a half marathon not 12.65," one user wrote.
Another user on TikTok questioned why runners weren't told.
"I think I can speak for a lot of people when I say that this is highly disappointing and I think we deserve some answers," the user said in her video, which now has nearly 40,000 views.
@veronica.wb Scandalous!! #chicagohalfmarathon #hoka #lifetime #halfmarathon #running #endurance #chicago ♬ original sound - Veronica Wolf-Boyle
Race organizers didn't immediately respond to NBC Chicago's request for comment on the matter. The HOKA Chicago Half Marathon is not affiliated with the upcoming Bank of America Chicago Marathon or the Bank of America 13.1.