Race hydration starts days before the race actually begins. Two days out, a runner needs to start “pre-hydration,” avoid alcohol and excessive/increased amounts of caffeine.
By Linda Mansfield, MD, Beacon Medical Group, Sports Medicine
You’ve trained, you’ve gained (endurance) and you are ready to run. But this spring’s temps have been below average. And while we’re thankful the hot weather is upon us, don’t forget that beautiful heat can pose a threat to driven, dedicated exercisers and athletes who tend to push themselves to their limits. During competition season, the risk (temptation?) is increased, especially when participants are not well acclimatized. As you train and compete this summer, here are a few reminders about the dangers of heat illness. It’s good to educate yourself on the ways to recognize, prevent and treat this potentially deadly phenomenon.
Heat illness falls along a continuum of symptoms. These are caused by dehydration, loss of electrolytes, and failure of the body’s thermoregulatory mechanisms. The types of heat illness in increasing severity are:
- Heat Cramps
- Heat Exhaustion
- Heat Stroke
Heat cramps are involuntary contractions of the muscles due to sodium depletion. The lower extremity muscles are most commonly affected. If you have ever had heat cramps, you can attest to the fact that these can be very painful. Initial treatment includes rest and cooling down, massaging the muscles and rehydration with an electrolyte solution similar to Gatorade.
Heat exhaustion is caused by dehydration or low sodium levels. Sweating still occurs, but may be decreased due to dehydration. Core temperature is elevated but is typically less than 103 degrees. Symptoms can include extreme fatigue, lightheadedness, muscle cramps, confusion and agitation. Treatment consists of rest, rapid cooling, and replacement of fluid and electrolytes.
Heat stroke is the most serious in the spectrum of heat illnesses and is a medical emergency. Temperature is 105 degrees or above and often in the 107-108 degree range. The symptom that differentiates heat stroke from heat exhaustion is the severity of the mental status changes. The changes in heat stroke range from moderate confusion and agitation to delirium, seizures and coma. The thermoregulatory system fails leading to multiple organ failure without prompt external cooling. The window of opportunity for treatment of this condition is approximately 30 minutes. It was previously thought that sweating fails to occur in heat stroke, but this has been found to be untrue in many cases of heat stroke.
It is important to remember that when a person becomes hyperthermic (overheated), oral and ear temperatures become unreliable. The most accurate body temp indicator is a rectal core temperature reading and should be monitored closely during the cooling process. In addition, the fastest way to decrease core temperature is immersion in an ice bath. The best situation is to have this available onsite (as we do at Sunburst) for an event where heat may pose a danger, as transporting to a medical facility may take longer than the time during which organ failure may start to occur. Finally, the best approach to heat illness is to prevent it with proper clothing, adequate hydration and acclimation to exercise in the heat.
Hydration—An important note; race hydration starts days before the race actually begins. Two days out, a runner needs to start “pre-hydration.” Also, it is good to avoid alcohol and excessive or increased amounts of caffeine. These substances have a diuretic effect in large amounts (or even small amounts if you do not imbibe them regularly). During the race, especially the half marathon and marathon, take advantage of the numerous water stops. When hot, drink more! The faster you run the more you sweat. A marathon runner can lose 0.8 to 2.0 liters per hour of running. If you get thirsty, you are already behind in your fluid replacement
Proper Clothing—Wear running socks — not cotton socks – which have been shown to decrease blisters. Break in you race shoes at least two weeks before the race. Women, make sure you wear a comfortable and supportive jog-bra. Men (and some women) who get irritated nipples when running can place Band-Aids and/or Vaseline over them.
Acclimatization— Ideally—to ensure your body is properly acclimatized—a competing runner should have four to seven training/exercise sessions in the heat for one to four hours at a time. Consider your training weather and especially, the weeks leading up to your race; if they were rather cool and race day is very hot, you will be less acclimatized and more at risk of developing heat illness, as may well be the case this year. Stay smart on the run! Remember—do not wait to get thirsty to hydrate!