Water is an essential nutrient for any active person. Two-thirds of our total body weight is water and it plays an important role in every major organ and system. To prevent adverse affects on the body, you should begin each workout fully hydrated.
If we do not replenish lost fluid, we will experience symptoms of dehydration, heat exhaustion and possible heat stroke. When exercising, we produce heat in our working muscles, which in turn, causes our core temperature to rise. The body cools down by perspiring and as the sweat evaporates from the skin, our core temperature will lower. The water we lose through sweating comes from blood plasma. Plasma is the means by which red blood cells get oxygen to our working muscles. Without sufficient water replacement while exercising, your total blood volume will decrease, compromising the oxygen-carrying abilities of your blood. This may result in a drop in blood pressure and cause nauseous, dizzy or faint feelings all of which are symptoms of heat exhaustion. Continuing to exercise through heat exhaustion can lead to a heat stroke. During a heat stroke, a dehydrated person cannot sweat fast enough to cool off, which may lead to a body temperature above 106 degrees Fahrenheit. At this point, you no longer sweat, and seizures, coma or even death may result if not properly and promptly treated.
During the dog days of summer, the high heat and humidity makes evaporation less effective so sweating will continue resulting in a greater loss of fluids making it even more important for you to pay attention to your hydration needs and levels.
If you are thirsty, you could already be dehydrated. As you sweat, blood volume decreases and the amount of salt in the blood increases. Since the hypothalamus in the brain measures the amount of salts in your blood, it will send a thirst sensation to encourage more drinking to dilute the salts.
To stay hydrated for exercise, you should drink 8-10 oz. of water prior to exercising and then drink 3-4 oz. every twenty minutes during your workout. If you have the option to weigh yourself before and after your workout, it is recommended that you drink one pint of water for every pound that you lost. These guidelines apply whether you are exercising outdoors or indoors.
For workouts 1.5 hours or less, plain cool water is best. Sports drinks contain a lot of sugar and therefore have a lot of calories in them so you need to be weary of their affect on your blood sugar levels and your daily caloric intake. Caffeinated beverages have long been labeled diuretics causing you to lose more fluid through urine. Even though recent research is investigating this claim, it is best to use plain water as fluid replacement.
Daily hydration tips.
Start your day with a glass of water. Drink something every two hours.
Breakfast items like fruit and milk with cereal contain a lot of water and can contribute to your daily water intake.
Carry water with you at all times.
Spruce up your water with a lemon or splash of juice for flavor.
Consume foods for lunch and dinner that contain water such as vegetables, fruits, yogurt and soup.
Check your urine, it should be pale in color rather than dark.