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Heat stroke, heat exhaustion or over-hydration?

Ah, summer. Time to get out and move. No one wants to miss the good weather, but ending up down and out due to heat stroke isn’t going to help you qualify for the Boston Marathon.

Preventing heat-related illness should be your first priority. If it’s very hot, it’s best to skip your workout or head for the air-conditioned gym instead. If you must exercise outside, try to do so in the early morning or late evening when it is cooler. If it’s hot, cut back on the intensity or duration of your workout. Drink water as needed during your workout – in hot weather, don’t substitute sports drinks for water. Water is much more rapidly absorbed from the gut, and if you’re working hard in hot weather you may be losing water at a tremendous rate to sweat. Save your sports drink (choose one with protein, electrolytes, and sugars) for after your workout.

Be careful, however, to not over-hydrate. Many novice athletes over-estimate how hard they are working/sweating, and consume far too much water during workouts. In addition to slowing you down with excess water-weight, over-hydration can cause serious physical problems (see below). The first sign of dehydration is thirst, and many experts suggest that during a workout you should only drink when you feel thirsty. If you suffer from dry-mouth during workouts (very common), try chewing a sports gum rather than drinking unnecessary fluids.

Signs and symptoms of over-hydration are very similar to those of heat exhaustion. The first symptom of both conditions is muscle cramping. If the condition is not corrected, over-hydration symptoms may include confusion, weakness, vomiting, and headache. Heat exhaustion symptoms may include confusion, weakness, vomiting, and headache. It can be easy to confuse the two conditions; in both cases, moving the victim to a cool location to rest is helpful, but while offering water to the heat-exhaustion victim is helpful, offering water to someone who is over-hydrated can be fatal.

Heat stroke and severe over-hydration (hyponatremia) are both medical emergencies (call 911). Symptoms of hyponatremia include disorientation, confusion, unconsciousness, and possibly seizures. Symptoms of heat stroke include disorientation, confusion, rapid pulse, fainting, and unconsciousness. Taking the victim’s temperature can easily distinguish between the two conditions.

Not surprisingly, heat stroke and heat exhaustion are more likely to strike on very hot days, particularly if weather conditions have suddenly become much warmer. For example, last year dozens of runners were taken ill from the heat in the Tel Aviv half-marathon when temperatures suddenly climbed from moderate into the high-90’s. Over-hydration most commonly occurs in endurance events, and tends to afflict novice athletes much more often than more experienced individuals.

Adjust your workout to the weather and stay safe. Mueller Sports Medicine offers a wide variety of braces, tapes, and supports to get you back in the game and keep you there. Don’t hesitate to contact us if you have any questions about our products.