The Edmonton Marathon in Alberta, Canada, which functions as a qualifying pathway to the Boston Marathon, inadvertently ran participants over a course that exceeded the official distance by more than 674 metres during the 2026 edition. Competitors who tracked their performance with GPS running watches became aware of the extended route length, approximately 0.41 miles beyond the standard marathon distance, and raised concerns online that race organisers initially brushed aside.

Following the criticism, event leadership acknowledged the miscalculation, explaining that construction activity surrounding Wellington Bridge necessitated an unintended route modification. The error carries significant consequences for runners, as some may have failed to meet the qualifying standards required for Boston Marathon entry or missed their targeted personal times, though officials clarified that official qualifying times rely on electronic chip timing rather than individual watch recordings. Race director Tom Keogh conceded the event fell short of expected standards and confirmed organisers are collaborating with Athletics Canada to determine how this year's results will be addressed.