A quarterly newsletter published by New
Mexico Senior Olympics, Inc.
| New Mexico Senior Olympics, Inc. | July 2003 |
Heat Disorders
and the Athlete
Modified from “Heat Disorders and the Athlete”
Dr. Bert Franks, Texas Christian Department of Education
Your Best Defense is a Good Offense
H
eat illness is one of the most common causes of disability in sport. Just a loss of two quarts of water in an average sized man can decrease athletic performance 10-20%.The consequences of a major heat-related disorder can range from minor discomfort to death. The approach to prevention and care is still an evolving program, but there has been a large reduction in deaths from this disorder in the past twenty years. The reasons for this decline are many: education of coaches and trainers as well as the athletes themselves; free availability of water during practices and events; clothing changes; and a more complete understanding of the role of electrolytes (salt, calcium, potassium, magnesium) in the body.
During exercise, the body’s temperature rises. Certain changes occur in the cardiovascular system in response to this heat stress. The flow of blood to the skin increases, which enhances heat loss from the skin but hampers blood flow to the core.
A fall in blood pressure is avoided because of a reduction in blood flow to the kidneys and other organs. It is important to remember that the use of diuretics, over the counter types as well as prescriptions (e.g. Lasix, and certain blood pressure medications), can interfere with the body’s ability to regulate heat. If the heat in the body rises to a certain level, system failure involving the liver, kidneys, and heart can result.
The more acclimatized and conditioned the athlete becomes, the greater is his/her ability to store and utilize water. They literally have a greater percentage of water to body weight.
Water dehydration is characterized by thirst and a decreased production of urine. Dehydration is treated by restoring fluids.
The symptoms of salt depletion are almost identical and can also become a problem in the person subjected to heat stress.
Because of low dietary salt and high losses of salt because of fluid loss, cardiac output and blood pressure are reduced. This condition is not characterized by thirst or relieved by ingesting salt-free liquids; it can only be treated with IV fluids in severe cases. In mild cases treatment includes the intake of salt solutions (Gatorade, et. al.). Certain low salt diets and medications for the heart and high blood pressure can make matters worse.
Differentiating between dehydration and salt depletion can be difficult because the symptoms are very similar. It is always best to have a sport medicine professional present at all athletic events, particularly those conducted in heat and humidity.
Heat illnesses can be divided into four types; in order of occurrence they are:
Heat cramps, Heat syncope, Heat exhaustion, and Heat stroke.Heat cramps
Treatment: rest, ice packs, and careful replacement of fluids
(Many people think the athlete who cramps in the early season is in poor condition. In some cases this is true, but many elite athletes cramp because of low body fat, which reduces their fluid storage ability.)
Heat Syncope
Treatment: Stopping activity, remove athlete from sunlight, apply cold towels, water replacement, use a fan to help cool the person.
Heat Exhaustion
Treatment: cool the body, fluid replacement, electrolyte replacement, removal from sunlight and heat, possible IV fluid replacement, use fans to cool the body, perhaps hospitalization.
Heat Stroke:
Treatment:
seek advanced medical help immediately, cool the body, IV’s, emergency room—fast.PREVENTION!
1. Provide unrestricted fluids during practices and events.
2. Workout in the cooler parts of the day.
3. Allow athletes to become acclimated.
4. Wear light colored and loose fitting clothing.
5. Provide water/fluid breaks.
6. Stress prehydration (many athletes respond only to thirst, not fluid loss). Drink fluids before you compete!
7. Restrict soft drinks and iced tea during the summer (they can lead to increased urination).
8. Drink cool/cold water; it is absorbed the fastest.
9. Know your medications; some can dehydrate the body or interfere with regulation of blood flow.
|
Dehydration and athletic performance:
A 150 pound man is about 60% water which is
|