TOPLINE:

Sudden cardiac arrest (SCA) during endurance races was rare and occurred mostly in men, with a higher risk observed near the finish of shorter races where men more often sped up in the final kilometre. Most runners survived with good recovery, but many cases had no clear cause.

METHODOLOGY:

• Researchers conducted an observational analysis using a prospective population-based registry and official race records in Paris to examine the incidence, clinical features, sex differences, and pacing patterns of SCA during endurance races.
• The analysis included over 1.2 million race participations (mean age, 38 years; 71.6% men) from the Paris 20 km, half marathon, and full marathon between 2011 and 2024, excluding 2020 when races were not held.
• SCA was considered race related if it occurred on the same day and within defined race time windows: up to 6 hours after the start for the 20 km and half marathon and up to 12 hours for the full marathon.
• Researchers collected standardised data on event circumstances, emergency response, hospital investigations, and patient outcomes.
• In the half marathon, pacing patterns were assessed by comparing runners' speed in the final kilometre with their average speed over the previous 5 km to measure late-race acceleration.

TAKEAWAY:

• Overall, 17 SCA events occurred, with no clear causes identified in 47.1% of cases. Most SCAs (88%) occurred in men, with an incidence rate of 16.9 per million in men and 5.7 per million in women.
• The risk of experiencing an SCA in the last kilometre was 15.2-fold higher than that at other points in the race (P < .001), particularly in shorter races.
• In the half marathon, men were nearly twice as likely as women to accelerate by more than 2 km/h in the final kilometre (ratio, 1.96; P < .001), and the gap widened with age.
• The overall survival rate was 88%, and all but one survivor had normal neurologic status at discharge.

IN PRACTICE:

"[The study] results may reflect a difference in self-determination in racing strategies between men and women, which may play a key role in the risk of SCA during this critical phase of the race," the researchers wrote.

SOURCE:

This study was led by Richard Chocron, Paris Cité University, Paris, France. It was published online on February 09, 2026, in EP Europace.

LIMITATIONS:

The study was observational and descriptive and could not prove cause-effect. Key data, including training load, environmental conditions, and training routines for non-finishers, were missing. Testing was not uniform, and no autopsies were conducted in two deaths.

DISCLOSURES:

This study did not have any funding sources. The authors declared having no competing interests.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.