Index

2007-10-10

Stressful exercise can be fatal

It happened again. A Michigan police officer died during the 2007 Chicago Marathon. An autopsy showed that a heart condition, and not the record-setting heat and high humidity, was what killed him. The temperature was 88 degrees Fahrenheit (31°C) by 10 AM, which broke the previous record of 84 degrees set in 1979. However, at least 49 people were taken to hospitals, while another 250 were treated onsite, many for heat-related ailments. The high heat index and the large number of casualties prompted director Carey Pinkowski to stop the race at 11:30 a.m., about 3 1/2 hours into the run, when the organizers became concerned they would not be able to cope with additional heat-related injuries as the temperature continued to soar. According to the organizers of the Marathon, approximately 45,000 runners registered for the race, but 10,000 did not show up. So, of the 35,000 who actually raced, about 300 required treatment or a hospital visit. That is about one percent.

Exercising during extreme heat and humidity causes a loss of body fluids as the body tries to keep cool by sweating. Drinking only water can be fatal because it results in hyponatremia, a sodium deficiency that may cause abdominal cramps and convulsions. Profuse sweating requires replacing sodium and potassium, two essential electrolytes. Drinking a glass of water with 1/4 teaspoon of salt or sports drinks helps to restore the electrolytes lost by sweating.

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