You are taking the advice regarding conditioning for the heat and humidity of Peachtree. Today you are running in the heat of the mid afternoon. You have done this before and you feel that your tolerance and acclimation is improving. Today, however, things begin to feel different. You started out feeling unusually well and running well. However, the last 15 minutes you become more fatigued and feel weaker than normal. There may be a little nausea and even a slight headache. You cannot tell if it is actually early muscle cramps or whether your muscles are just aching. As you begin to concentrate, it is harder to focus on where you have been and you may feel a little dizzy. Realizing these symptoms as being unusual, you stop, take extra fluids, walk in the shade and gradually the symptoms resolve. You still feel a slight headache the rest of the day and the next day your muscles are a little sorer than normal. The runner who has experienced these warning symptoms has identified a condition called heat exhaustion. It occurs when the production of heat is greater than the ability to dissipate heat and the body temperature rises. Recognizing this, taking appropriate measures to allow body temperature to cool can avoid the potential life-threatening condition called exertional heatstroke.
In the race, when there are external factors that push runners beyond sometimes their normal comfort level, some runners ignore these symptoms and get into trouble. Continuing to pursue exercise with the above symptoms leads to deteriorating mental capabilities. Bizarre behavior can occur, along with confusion, disorientation and eventually coma. It is not too dissimilar to a progressive alcohol stupor, in that the brain is being significantly limited in its ability to function by increasing body temperature.
The concerning issue with heatstroke is that if it reaches a certain point, it can become a self perpetuating, life-threatening problem. As the body temperature increases above 104 degrees, the muscle cells themselves have difficulty sustaining the proper environment. Energy is consumed within the cell to attempt to maintain a stable environment. This itself generates further energy loss and further heat production. Even if the runner stops at this point, the need for the cells to support themselves can continue to generate heat that can further raise the body temperature. The runner can go into a downward spiral, even if he quits exercising. As the body temperature further increases, the proteins begin to breakdown. The tissues literally begin to cook themselves.
The role of the runner is to recognize these earlier symptoms and to stop and cool down without progressing to the more significant mental and physical problems. Our job as the medical team is to rescue those who fail to recognize these symptoms and push too hard.
Be prepared on race day by understanding the increased psychological pressures and the increased potential to push beyond your normal comfort level. If you are feeling unusually fatigued, particularly if it is associated with nausea, headache and dizziness, stop, take extra water, sit down in the shade and rest, then complete the race after you feel better. Pushing in hot, humid conditions for a personal best time or to make a personal point on your conditioning is not worth the risk to your health and well-being.
Fortunately, heat exhaustion and its more devastating consequence, exertional heatstroke, are rare. Predicting who will experience these factors is difficult to impossible. Clearly, the motivation of the runner to push beyond his normal comfort level in hot, humid conditions seems to be one consistent finding. Dehydration, increased alcohol consumption the night before, use of stimulants and recent viral infections also may have predisposing significant causes.
It is the role of each runner on Peachtree to recognize the potential and to pace themselves appropriately. At the completion of a successful race, the runner will hear well done and it will not be done by the medical team, referring to their muscle tissues.
–Dr. Joe Wilson
Runner since 1966
Medical Director since 1987
Cardiologist with Cardiology of Atlanta and St. Joseph’s Hospital