The coming weekend is predicted to be the hottest so far this year, and hotter than a usual June weekend locally. That means it’s time to be mindful of the impact hot weather can have on runners.
Along the coast, we get a double whammy of heat and humidity. Humidity above 50 percent can cause the heart beat to increase on average 10 beats per minute.
That’s a significant increase, enough to interfere with a heart rate monitor-based training. Heat has the same effect, with temperatures above 90 degrees leading to a heart rate spike of about 10 beats per minute.
Heat stroke, the most severe heat-related illness, is one of the three leading causes of death among athletes and the leading cause in July and August, according to the American College of Sports Medicine. Fortunately, it’s preventable by taking simple precautions and by paying attention to early warning signs.
Heat illnesses range from heat cramps and heat exhaustion to heat stroke. Early indicators of heat illness include muscle cramps, headache, clammy skin, nausea, thirst or disorientation. At the first sign of any of these symptoms, finding the nearest source of water and shade can prevent a mild case from becoming serious.
According to the experts at the American College of Sports Medicine, heat exhaustion is essentially dehydration severe enough to effect the cardiovascular system. To prevent dehydration, it’s important to drink before and during exercise.
The American College of Sports Medicine guidelines advise drinking 16 ounces of water or sports drink before exercise, and then 4 to 8 ounces every 15 or 20 minutes while exercising.
Plain water is fine for exercising that lasts less than an hour. Longer runs should include electrolyte-replacing drinks that include sodium, potassium and carbohydrates. Freezer pops with electrolytes are a post-run alternative.
Don’t forget to wear a hat or visor, and be sure that canine running companions will have plenty of opportunities to stop for water. Hot-weather running can be safe and fun, but shouldn’t be taken for granted.