Whether you are sprinting or running at a moderate pace, drinking water while you exercise is important to prevent dehydration and improve your post-exercise condition. When you are running, you lose water through breathing and sweating. Mild dehydration alone can affect your ability to complete your exercise or perform competitively. Drinking too much water can also be dangerous, which makes it important to know the right amount.
Benefits of Water
Drinking water balances your body’s fluids, and it helps your heart transport essential nutrients, waste product and oxygen through your blood cells, according to Len Kravitz, Ph.D, a coordinator of exercise science at the University of New Mexico. Preventing dehydration by consuming water can make runners feel more alert and helps you exercise for longer, according to Cathleen Murakami, the author of “Morning Pilates Workouts."
How Much You Need
As a runner, it is important not to measure the amount of water you drink through how much you sweat, as this can lead to low sodium levels. Listen to your body and drink water when you are thirsty. However, it is possible that you only notice you are thirsty when dehydration occurs. As a guideline, increase your water intake when running in hot temperatures and aim to drink 6 to 12 ounces of water every 15 to 20 minutes during a moderately paced run. The American Dietetic Association recommends athletes stay keep up their fluid intake before, during and after a run. Drink about 16 of water two hours before your run and about 8 to 16 ounces 15 minutes before.
Signs of Dehydration
The symptoms of dehydration are not always apparent during a moderately paced run. Common symptoms are dry mouth, thirst and a headache. Dehydration can also make you feel tired while exercising. Severe dehydration can occur rapidly while running -- particularly in hot weather -- and it can lead to dizziness, seizures and vomiting. Some mistake dehydration for exhaustion during exercise, which can exacerbate the symptoms of dehydration.
While it is difficult to drink too much water, it is possible. It can lead to water poining, also known as dilutional hyponatremia. It occurs when you drink so much water that it flushes out the sodium in your blood to dangerously low levels. Common symptoms include nausea, headaches, fatigue -- or restlessness -- cramps and in extreme cases seizures and death, according to Medline Plus. Other than long-distance runners performing in a marathon or endurance sport, most people are not capable of overdosing on water.