With increases in temperatures during the summer months, ensuring adequate hydration is extremely important, especially during activities requiring physical exertion. Every cell and system in the human body relies on water to survive and to work correctly and efficiently, but water is lost every day through sweating, urination and breathing. Sweating is the body’s cooling mechanism, so naturally we sweat more when outdoor temperatures are higher or during exercise. A combination of hot, humid temperatures and physical activity can easily put the body into a state of dehydration. Dehydration decreases the ability of the body to regulate core temperature and decreases blood flow, both of which can have a detrimental impact on exercise performance.
Certain people will be more susceptible to dehydration than others, i.e. children lose water more quickly due to smaller body size, while older adults have difficulty conserving water and have a decreased sensation of thirst. Anyone who works or exercises in hot and humid conditions is also more likely to become dehydrated due to an increased level of sweating. Humidity makes it difficult for sweat to evaporate from your skin, which means it is harder for your body to regulate its temperature and keep cool. Although heavy and prolonged exercise makes people most at risk for dehydration, there is a cumulative effect. This means with inadequate fluid intake over a few days, even mild or moderate exercise can create a state of dehydration. For athletes, mild dehydration of 1-2% of body weight can decrease the ability of muscles to use glucose, which diminishes aerobic performance and causes fatigue more quickly. Therefore, it is very important to ensure proper hydration in the days leading up to races or games.
How to tell if you are dehydrated:
- Little urine output and/or urine that is darker than usual
- Dry mouth, thirst
- Dizziness, lightheadedness
- Muscle cramps
Drinking fluids and replacing electrolytes is the easiest and quickest way to treat dehydration. If you have any of the above symptoms and think you may be dehydrated, drink small amounts of water frequently in order to prevent an upset stomach. Sports drinks can also be helpful in treating or preventing dehydration, but take caution as the sugar in sports drinks can cause diarrhea. Eating foods high in water content, such as fruits and vegetables, will help in the rehydration process; and be sure to avoid anything that will continue to dehydrate you further, such as caffeine and alcohol. Severe dehydration will require a trip to the hospital for rapid hydration through an intravenous line. Symptoms of severe dehydration include loss of consciousness, rapid or weak pulse, low blood pressure, and confusion. Untreated severe dehydration can lead to complications, such as heat stroke, and can damage kidneys and muscles. Heat stroke occurs when the body overheats and is no longer able to sweat and cool itself down, usually due to prolonged physical exertion in hot conditions. This is extremely dangerous and requires immediate medical attention, before brain or other organ damage occurs. A milder form and precursor to heat stroke is heat exhaustion, which has symptoms such as heavy sweating, lightheadedness, and muscle cramps. It is very important to treat heat exhaustion before it becomes heat stroke, by moving the person into a cool, shaded area, cooling off with wet towels, and giving liquids if possible. If symptoms continue to worsen, call for emergency medical attention.
How much do you really need to drink?
Although there are many recommendations for how much water to consume, a general rule of thumb is to consistently drink throughout the day, before you feel thirsty. Exercisers will need to consume more than non-exercisers due to water loss through sweating. In the hour or so prior to a workout, try to consume 1-3 cups of water. During exercise, if possible, drink about ½ cup or a few mouthfuls every 15-20 minutes. This will help to prevent dehydration and is especially important if the weather is hot, or the activity is particularly long and strenuous. A handy trick to know how much to drink after finishing a workout, is to weigh yourself before and after. For every pound that you have lost during the activity drink about 3 cups of water. If you weigh the same amount before and after, it likely means you hydrated adequately throughout the activity, and can just continue drinking normally for the rest of the day.
Keeping cool and staying hydrated should be a priority in the hot summer months. Dehydration negatively impacts the body and can lead to a decrease in athletic performance, heat exhaustion or even heat stroke. Drinking water consistently throughout the day, and increasing this amount before and after exercise will help to keep you hydrated and safe during the summer.