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Hiding From Heat Injuries
Hiding From Heat Injuries
By Neil McLaughlin
May/June 2009
Two runners were traversing their usual route on a hot, humid, summer day. One was sweating profusely with a nice white, salty ring developing on his dark hat. At the same time his partner was running nice and dry, save for the occasional spray she was catching from her friend. You may have an opinion as to which runner is more at risk for a heat injury, but the truth is both runners are at risk for different conditions related to heat exposure due to their differing metabolism.
Let us start with the human fountain first. I can relate to him as this is my quandary. This runner cannot replenish fluids fast enough to keep up with the excretion of fluid and salt that is taking place. The good news for this runner is that the sweating and subsequent evaporation is serving to cool his internal body against the heat, thereby keeping body core temperatures at safe levels. The bad news is he is dehydrating and losing valuable electrolytes including sodium, potassium, and chloride. If this continues, performance will suffer, muscles will not be able to function properly, and ultimately it becomes a major health risk with a potential for death. In recent years we have learned more about a condition known as hyponatremia--a potentially fatal condition which is the result of dangerously low electrolyte levels. This condition can actually be heightened by drinking plain water, as this further dilutes the electrolyte levels in the body.
Now go to our high and dry runner. She does not noticeably sweat at all no matter the conditions. The problem with this is that sweating is part of the natural cooling mechanism of the body, and without it our core body temperatures can rise to unsafe levels, a condition known as hyperthermia. In the worst-case scenario on a long hot run, the runner who does not sweat much may develop heat stroke, a potentially fatal condition.
The problem with heat injuries is that they can sneak up on you, and because dehydration and hyperthermia can often occur with disorientation and diminished mental capacity, the runner will not be in a state to help himself or recognize he is in trouble. Heat injuries can happen to runners of all abilities and experience levels. That is why it is important for others to stay aware. If you come upon a runner who appears in distress, take note of whether he is sweating; it makes a huge difference in the approach.
The runner with dehydration and possibly hyponatremia needs fluids and electrolytes, while the runner with hyperthermia and possibly heat stroke needs to get the core body temperature cooled.
We can do a few things to learn how to deal with the heat. First, recognize how you do in hot, humid conditions. Which type of runner described above are you? If you are the "sweater" you need to be concerned with fluid and electrolyte balance. The Gatorade Sports Institute recommends at least 5 ounces of fluid for every 15 to 20 minutes of exercise. Sports drinks typically have a 4% to 8% concentration of carbs, and around 100 to 110 mg of sodium per 8 ounces of drink for optimal replacement. Another trick is to weigh yourself before and after runs. For every one pound of weight you lose you have lost about 16 ounces of water, since most weight lost with exercise is water weight. For the "dry" types who do not handle heat well, you may have to run earlier in the day or evening to avoid the heat of the day. And though sunscreen is very important this time of year, be careful to avoid those that may inhibit sweating. Many of these recommendations go for both types.
This information just scratches the surface, as we are all individuals as to how much we sweat, which drinks our body will tolerate, etc. While we spend a lot of time thinking about other types of injuries, do not forget the potential of serious thermal related injuries.
Dr. Neil McLaughlin and Dr. Ronald Kulik are proud to announce the addition of Dr. Rose Moeser to the staff of Commonwealth Chiropractic Center of Reston. Dr. Moeser grew up in the region and graduated from George Mason University; she then received her Doctor of Chiropractic Degree from NY Chiropractic College in 2008. Dr. Moeser is from a well known running family in the area and is also certified in Active Release Technique (ART). Dr. Moeser is a welcome addition to the staff of Commonwealth Chiropractic Center of Reston and to the area running community.