Acute cardiac care & resuscitationResearch article
Meteorological and Environmental Factors Associated With Sudden Cardiac Arrest During Marathons in Japan
- nationwide race-level study
Authors' conclusion
In Japanese marathon races held predominantly in autumn and winter, lower ambient temperature at race start was associated with a higher risk of SCA, whereas no significant association was observed for ambient air pollutants.
Study context
- Population
- Runners participating in Japan Association of Athletics Federations-certified full marathons in Japan between April 2011 and March 2020
- Participants
- 4.53 million runners
- Comparison
- Associations of meteorological conditions and ambient air pollutants with sudden cardiac arrest (SCA) during marathon races
Main finding
As reported in the abstract
SCA cases
cases of SCA identified
75
Further findings
| Outcome | adjusted incidence rate ratio (95% CI) | |
|---|---|---|
| SCA risk by ambient temperature at race start · inversely associated; higher risk at lower temperatures | 0.94 (0.90–0.99) | |
| 0.512Adjusted incidence rate ratio (log scale) |
- SCA risk by ambient temperature at race start: adjusted for race characteristics and participant composition
SCA risk by ambient air pollutants
- No statistically significant associations between ambient air pollutants and SCA risk
Original publication
Meteorological and Environmental Factors Associated With Sudden Cardiac Arrest During Marathons in Japan. JACC Adv. Published 29 June 2026. doi:10.1016/j.jacadv.2026.102965
Summarised from the published abstract; every number is checked against it