As spring approaches, and with it the return of warmer weather, it might be time to think about some of the ways to exercise more safely in the heat and humidity. It is never too early to think about training safety. Even moderate exercise in hot conditions can result in dehydration and other heat related illnesses. Dehydration occurs when an athlete’s fluid loss results in a weight loss of 1-2% depending on body weight. A fluid loss of more than 3% can lead to some of the more severe heat related illnesses.
Signs of Dehydration
- Thirst
- Irritability
- Headache
- Dizziness
- Nausea
- Weakness
Most athletes can avoid dehydration by simply replacing the fluid they lose while exercising and avoiding the associated weight loss. In warm weather conditions, dehydration can affect performance in less than one hour. This means that even well conditioned athletes are at risk, since they are the ones that will be exercising for prolonged periods.
Steps to Avoid Dehydrating
The most crucial point to remember when exercising in warmer weather conditions is not to rely on thirst to monitor fluid intake. Drink at least 15-20 oz. of water about two hours before exercising. About 10 minutes before you start drink another 6-10 oz. If you are engaged in prolonged aerobic activity, it is a good idea to drink 6-10 oz. every 10-15 min. until finished..
When the activity is over, the athlete should consume 20 oz. of fluid for every pound of lost body weight. In extreme heat and humidity, it will help to drink electrolyte replacement fluids. These help in fluid maintenance and normal body function. Drinking cool, but not cold, beverages is recommended. Usually around 50-60 degrees F.
Recognizing Heat Related Illnesses
If an athlete experiences signs of dehydration, it is a good idea to stop before the onset of heat illness. There are three types of heat illnesses. Each one is always preceded by dehydration.
- Heat Cramps- Heat cramps are the least severe of the heat illnesses. They are causes by fluid and electrolyte loss. These cramps manifest themselves as sharp pains in the muscle that don’t disappear with time. The athlete should cease activity and drink electrolyte and fluid replacement drinks, cool down with wet towels and get out of the sun.
- Heat Exhaustion-Heat exhaustion manifests itself as a rise in body temperature, followed by nausea, vomiting, dizziness and a headache. Without hydration, heat exhaustion will progress and the athlete will experience lack of coordination, cramps, heavier sweating and "goose bumps" and tingling. Get out of the sun. Replace fluids and electrolytes, cool with wet towels and lie down with your legs elevated above your heart. Seek Medical Attention! Untreated heat exhaustion can result in heat stroke.
- Heat Stroke- This is a life-threatening situation that requires immediate medical attention. Heatstroke can (and does) occur with or without the signs of heat exhaustion being apparent. Symptoms of heatstroke include tiredness, weakness, confusion, strange behavior, disorientation and unconsciousness. Heatstroke is a failure of the system that monitors the body's temperature. Sweating stops and the skin is warm and dry. Any combination of these symptoms can indicate heat stroke. Convulsions or seizures can occur. Coma and death are also possible. Heatstroke is a medical emergency. Get Immediate medical Attention! Get the runner out of the sun, remove all clothing, and immediately apply ice to their body or put the runner in cold water.
Laying down a good fitness base and preparing the body for exercise in the heat and humidity is a good first step to avoiding dehydration and heat injury. Starting an intense aerobics program in hot conditions may not be advisable. As with any fitness program, consult a physician before you startCommon sense and planning can help you run problem free throughout the warm season.
- Hydrate
- Exercise at the coolest time of the day.
- Wear proper attire.
- Replace electrolytes.
- Stay out of the sun.
- Don’t over exert!
Following these simple rules should help you have an enjoyable, injury and illness free, warm weather fitness season.
Sources:
Southern Nevada Health District "Recognizing and Treating Heat-Related Ilnesses"(Accessed March12, 2010)
Clive Reed - Clive Reed is 54 years old and an avid runner, cyclist and swimmer. He has a BA in Psychology, with courses in English, Linguistics and ...
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