While you can go weeks without food, your body can only go an estimated three to five days without water. Water is your body's principle chemical component with about 60 percent of your body being made up of the substance, suggests MayoClinic.com. Along with allowing you to stay alive, water also plays an essential role in your muscle's abilities to work and perform. As such, a lack of water, or dehydration, can lead to unwanted effects in regard to exercise.
How Muscles Use Water
Water is essential for muscle cells to get the necessary oxygen and nutrients they need to create energy. Water is used in the cardiovascular system to make up the bulk of your blood. Blood transports oxygen and nutrients from the foods you eat and the air you breathe through the arteries and into the capillaries throughout your muscles. When you don't drink enough water, your blood volume is effected, restricting how fast the blood can transport the substances your muscle cells need in order to create energy to keep exercising.
Cramps
An effect of not getting enough water during exercise are cramps. When your muscles are not getting the oxygen and nutrients they need, they can tense up as a protective reaction to stop energy use. This results in the pain and tightness associated with cramps. Dehydration can also cause cramps through an electrolyte imbalance. Exercise causes you to sweat, which can lower water levels and throw off the balance of key electrolytes like potassium, magnesium and calcium. Muscles rely on this balance to operate correctly, especially at levels of higher activity during exercise.
Dehydration Dangers
Not staying hydrated before, during and after exercise may also result in potentially dangerous side effects. If you're already low on water, and you increase water loss through sweat during exercise, dehydration can quickly set in. Dehydration can lead to mild symptoms like dry mouth, headache, dizziness or feeling lightheaded, or it can grow into symptoms of severe dehydration, such as low blood pressure, high heart rate, confusion, fever and unconsciousness. If at anytime you feel lightheaded, dizzy or like you're going to lose consciousness, stop exercising immediately and drink plenty of water.
Water Recommendations
To help your body perform at its best during exercise, it's important to stay hydrated, even when you're not performing a physical activity. There are several different recommendations on how much water your body needs to stay hydrated. The most basic is the "eight-by-eight" rule, or 8 cups of water eight times a day. For more specific water guidelines, the Food and Nutrition boards recommends 2.7 liters for women and 3.7 liters for men each day.
