Most runners have been warned of the dangers of life-threatening cardiac conditions, but many aren’t aware that experiencing heat stroke is far deadlier. 

"This research shows that heat stroke is a real threat to marathon and long-distance runners; however, there are no clinical studies of potential strategies to prevent heat stroke during these types of events," the study’s lead author and cardiologist at Tel Aviv Medical Center, Dr. Sami Viskin, said in a press release. The findings appear in the Journal of the American College of Cardiology.

The study reviewed data from deaths and hospitalizations of long-distance runners who participated in 14 popular races in Tel Aviv, Israel, between March 2007 and November 2013. Out of the 137,580 runners, the researchers looked at only two experienced serious cardiac events, but neither of them were fatal or life-threatening. Meanwhile, there were 21 cases of heat stroke reported by the hospitals. Two of them were so severe they died and another 12 were life-threatening.

Life-threatening events occurred when a patient was sent into the intensive care unit and breathed using mechanical ventilation. Even though heat stroke threatens runners’ lives 10 times more than cardiac events, heart conditions are given a lot more awareness and concern than heat stroke, according to researchers. Runners who participate in organized teams or associations are oftentimes required to undergo electrocardiography (ECG) screening to evaluate the heart’s activity. When researchers asked 513 runners at a 2013 race, 35 percent of them reported an ECG and 46 percent reported having one done in the last five years.

There needs to be a shift toward heat stroke prevention, considering how high the dangerous incidence levels are among runners. Heat stroke occurs when the body temperature rises 104 degrees or higher and causes overheating usually during physical activity. If heat stroke goes untreated, it can quickly damage the brain, heart, kidneys, and muscles, according to Mayo Clinic.

Watch Out For These Signs:

  • High body temperatures
  • Nausea and vomiting
  • Rapid, Shallow Breathing
  • Significant increase in heart rate
  • Abnormal mental state or behavior(confusion, agitation, slurred speech, delirium, and seizures)

 

Avoid Heat Stroke By:

  • Wear loose fitting, lightweight clothing
  • Seek air conditioning or shade
  • Avoid sunburn
  • Stay hydrated before, during, and after physical exertion
  • Acclimate to the heat before exercise
  • Double check if your medications make you more susceptible to heat exhaustion

 

"It's important that clinicians educate runners on the ways to minimize their risk of heat stroke, including allowing 10-14 days to adjust to a warm climate, discouraging running if a person is ill or was recently ill because a pre-existing fever impairs the body's ability to dissipate additional heat stress, and developing better methods of monitoring body core temperature during physical activity," Viskin said. 

Source: Viskin S. Journal of the American College of Cardiology.2014.