The Wonders of Plain Old Water
We all know that we need to practice before a race. We need our quads in top form, and will move Heaven and Earth to get the parts delivered and the engines broke in by race day. We stretch out before our race and we make sure that our quad is warmed up before that metal gate slams the dirt. But do we take the time to really make sure our bodies are ready for the task before them? Sure we practice, and we drink some Gatorade, but do we really know how much is enough practice or how much is enough fluid? We sure didn't.
Did you know:
- • Dehydration can happen surprisingly fast and can affect an athlete's performance in less than an hour of exercise -- sooner if the athlete begins the session dehydrated.
- • Dehydration of just 1 to 2 percent of body weight can negatively influence performance.
- • Dehydration of greater than 3 percent of body weight increases an athlete's risk of heat illness (heat cramps, heat exhaustion, heat stroke).
- • High-body-fat athletes can have a harder time with exercise and can become dehydrated faster than lower-body-fat athletes working out under the same environmental conditions.
- • Poor acclimatization/fitness levels can greatly contribute to an athlete's dehydration problems.
- • Medications/fevers greatly affect an athlete's dehydration problems.
- • Clothing, such as dark, bulky, or rubber protective equipment can drastically increase the chance of heat illness and dehydration.
- • Environmental temperature and humidity both contribute to dehydration and heat illnesses.
- • A relative humidity of 35 percent and a temperature of 95 degrees Fahrenheit are likely to cause heat illness, with heat stroke likely.
- • A relative humidity of 70 percent and a temperature of 95 degrees Fahrenheit are very likely to cause heat illness, with heat stroke very likely.
Most often, heat-related illnesses are preventable conditions. However, they can have significant consequences, including death, if left untreated. Heat Injuries are traditionally divided into two main categories-heat exhaustion and heat stroke. These conditions can overlap in many ways and exist within a range of severity. As a patient's body temperature rises, heat exhaustion can rapidly progress to heat stroke.
Heat Exhaustion and Heat Stroke
Heat Exhaustion develops when the body encounters excessively high temperatures that it is not used to managing. It occurs at body temperatures that are very high, but usually less than 40 degrees Celsius, or 104 degrees Fahrenheit. The symptoms of heat exhaustion are not very specific, but ultimately relate to a state of dehydration, which is the condition's primary characteristic. Symptoms may include weakness, headache, and nausea.
Heat Stroke is severe injury from high body temperatures that causes damage to many organs, particularly the central nervous system, which include the brain and spinal cord. In contrast to heat exhaustion, patients suffering from heat stroke will have temperatures that are usually greater 104 degrees. Heat stroke may be divided into two categories-exertional and classic.
Exertional Heat Stroke patients are usually people who are exercising in excessively warm conditions. Their bodies cannot manage the stress of the physical activity and the hot environment together.
Classic Heat Stroke patients are often elderly or debilitated people who are in warm environments for too long. The elderly are especially at risk to the heat, as the body is less and less able to handle heat as it ages. Elderly people may also have pre-existing illnesses that make them more susceptible to heat stroke, or they make take medications that affect the body's ability to manage hot temperatures. Elderly people, who, for economic reasons, are not able to get out of the heat, are at great risk for heat stroke.
Heat Transfer
In order to understand heat-related illnesses you need to know something about the way the body normally gets rid of heat. There are four ways the body transfers heat: radiation, evaporation, conduction, andconvection.
Radiation occurs when the body turns heat into electromagnetic waves. In other words, waves of heat can escape from the body directly into the surrounding air. This is the primary way that human beings are able to lose heat from their bodies in very hot environments.
Evaporation is the transfer of heat that occurs during the transformation of liquid to gas. Evaporation of sweat is another significant method that the body uses to cool down.
Convection and Conduction are secondary ways for the body to lose heat after radiation and evaporation. Convection is the passage of heat into the air and into the vapor that surrounds the body. It is different from evaporation in that the heat does not transform to the gas phase, as it does in evaporation. Conduction is the transfer of heat through physical contact.
What Happens When it Gets Too Hot
In hot environments, the body initiates several processes to lose heat. First, the anterior hypothalamus, the body's thermostat in the brain, signals the body to open up blood vessels near the skin's surface so that heat can be transferred outside by the methods listed above. This vessel dilation is possible because blood is shunted away from the body's core. The hypothalamus also mediates sweating and tells the body to respond to the heat by taking off clothes and seeking a cooler environment.
When it becomes too hot, however, the body's ability to cool down becomes overwhelmed. Symptoms like fatigue, headache, muscle aches, confusion, and even coma can occur, depending on the severity of the condition.
This overwhelming of the body's means of handling heat can be caused by a very warm environment or excessive exercising in the heat, as discussed before. Also, though, patients may get overheated because of certain illnesses like hyperthyroidism (high thyroid hormone level) or infections causing fever. Additionally, some medications can cause high body temperatures.
Symptoms and Signs
There are a variety of symptoms associated with heat-related illnesses. Heat exhaustion patients may have vague complaints of symptoms that come on slowly. These can include:
- • Headache
- • Weakness
- • Lightheadedness
- • Muscle aches
- • Muscle cramps
- • Agitation
Heat stroke patients can have the same complaints as heat exhaustion patients, but they also suffer central nervous system problems, which can include:
- • Confusion hallucinations
- • Bizarre behavior
- • Altered Mental Status
- • Unconsciousness
- • Seizure
- • Coma
It was once thought that heat stroke patients did not sweat, but this inability to sweat is variable, and often strikes the patient at the latest stages of the condition.
Heat stroke patients, because of the resulting multi-organ damage, may also complain of blood in the urine or stool, decline in the amount of urine produced and shortness of breath, among other problems.
Other symptoms
There are secondary categories of heat-related illnesses to watch out for:
- • Heat syncope occurs when a person overheats and then faints.
- • Heat cramps are muscle contractions associated with electrolyte or mineral abnormalities caused by the heat.
- • Heat edema is characterized by swelling in the arms and legs because of the heat.
- • Prickly heat is a heat rash that is red and very itchy.
Treatment
There is a lot that you can do for a person suffering from a heat-related illness. If you see someone who appears to be suffering from a heat-related illness, you should call for help immediately. In the most rare, severe cases, you should start cardiopulmonary resuscitation (CPR), if necessary. If the person is not a trauma patient (has not been in an accident, fight, or fall), you should move the individual from the hot environment to a cooler location. Next you can sprinkle lukewarm water on the skin and fan the patient; this will encourage evaporation. You can also apply ice packs to the neck, underarms, and groin.
In the emergency room
Once a patient has been taken to the emergency room, the cooling process will be continued. The doctor may use a cooling blanket and some other more aggressive methods, but in general, treatment is similar to the methods that should be initiated immediately, including fanning and ice packs.
The doctor may order tests to assess organ damage. These tests can include electrolytes or minerals, blood-clotting tests, a urine analysis, creatine phosphokinase (a muscle enzyme quantification), and a head computed tomography (CT or cat) scan. Heat stroke patients are admitted to the intensive care unit. Heat exhaustion patients are admitted to a regular floor bed in the hospital. When patients are released from the hospital, they should have a place to go to avoid the heat, and they must be able to rehydrate themselves.
If caretakers are aggressive with these cooling techniques before delivering the patient to the hospital, and the emergency department is able to treat any related organ damage, then there is a good possibility that the prognosis will be excellent.
Prevention
Heat-related illnesses are often preventable. When hot weather is expected, the elderly and debilitated must be ensured access to cool, air-conditioned shelter. People should be encouraged to wear light-colored, loose clothing and bathe in tepid water. Also, hydration is critical, and people in hot weather should increase their fluid intake substantially.
To avoid exertional heat stroke, athletes should not exercise in extreme heat, and coaches/trainers should be aware of the symptoms of heat-related illnesses. Athletes also must stay well-hydrated.
Current heatstroke survival is 90% to 100% --greatly improved from a rate of about 20% early in this century. This can be attributed in large part to improved initial management with early and aggressive cooling measures.
Now we know all the big stuff (and trust me this is just the tip of the iceberg; I have given you the quick version).
Summary
Dehydration is a nasty business and something many of us often think afflicts only desert-dwelling members of the French Foreign Legion or nomadic bands of camel jockeys. Yet, surprisingly, more and more studies are suggesting that many of us are living in our own personal hydration hells. The result? Sluggishness, dulled senses, a general sense of fatigue and an all-around lack of peak performance.
Hydration is a crucial part of life itself, and water losses of a mere 1 percent or 2 percent of your body weight can impair functioning both mentally and physically. Losses of 7 percent or more may bring you down for the count, disrupting your delicate internal balance and resulting in a total body collapse.
The average sedentary adult male needs at least 12 cups of fluids per day. This means decaffeinated, nonalcoholic beverages, soups or foods.
People who exercise regularly or live in inhospitably hot environments should increase their intake. Ideally, you'll do your body a favor by simply drinking 12 tall glasses of water a day-why make Mother Nature's machinery work for its water by leeching it from otherwise dry foods? Keeping properly hydrated also means you'll help maintain your body's electrolyte balance.
Here are some guidelines for avoiding dehydration and keeping your water levels topped off appropriately:
Don't Go For The Gold
It's not a discussion topic for good company, but watching your urine may be the best way to eyeball your body's hydration. Dark, gold-colored urine is a sure sign that you're low on fluids. Drink enough fluids, especially when you're exercising, to aim for light-yellow or, better yet, almost clear urine.
Don't Obey Your Thirst -- Beat Your Thirst
Hydration needs to be an ongoing process. If you relied on your thirst alone for proper hydration, you'd put back only about 50 percent to 75 percent of what you need.
Know Your Weight
Knowing your body weight pre- and post-exercise is a good way of keeping track of fluid loss. A 150-pound individual who loses 3 pounds after a heavy-sweat session has lost 2 percent of body weight--more than enough to adversely affect physical and cognitive functioning.
Drink Early and Often
Drink one to two cups of fluid, preferably water, at least one hour before exercise and keep sipping half a cup or more for every 15 to 20 minutes of your workout.
In Other Words
Make drinking water a habit, at least 12 tall glasses a day. Be a bottle baby (carry a bottle of water with you everywhere and use it). Drink water regularly before, during and after exercise or races.
For now, be safe, drink water, call your Mom.
Mom.
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