Incidence and Management of Exertional Heatstroke in Marathon Runners

A study of 136,161 participants in the Boston Marathon reported an incidence of exertional heat stroke (EHS) at a rate of 3.7 cases per 10,000 runners, with a 95 percent confidence interval ranging from 2.8 to 4.9. Research indicates that younger and faster runners are more susceptible to heat stroke during marathon events, particularly in hot and humid conditions. Emergency response for runners showing symptoms involves moving to a shaded, well-ventilated area, loosening clothing, and drinking water cautiously at regular intervals, alongside cooling measures like applying damp cloths.

Gradual heat acclimatization is recommended by ultrarunner Patrick Reagan, suggesting maintaining most regular training routines while shifting only a few runs to hotter parts of the day each week. Acclimatization to elevated temperature and humidity typically requires 10 to 14 days to develop effectively.

Heat stroke has been identified as a significant threat to endurance athletes, with data showing it is ten times more likely than cardiac events to cause life-threatening incidents during races held in warm climates. For prevention, athletes are advised to begin exercise in a well-hydrated state by consuming 6 milliliters of fluid per kilogram of body weight every two to three hours before activity. During exercise, continuous hydration is critical.

Additional guidance for runners includes staying in air-conditioned environments as much as possible before competing to maintain a lower core body temperature, and avoiding clothing like sweat suits or long sleeves that may increase heat retention. If systolic blood pressure falls below 90 during symptoms of heat illness, emergency medical services should be contacted.

Analysis of medical records from marathon events over several decades shows multiple cases of severe exertional heat stroke requiring medical intervention. Preventative measures and prompt treatment protocols are emphasized for managing exertional heat illness, from sports fields to emergency departments. This information is relevant to the broader sports community.