Your body is 78% water and all activities of the body require energy, which is dependent upon your body’s ability to convert protein, fat and carbohydrate to energy. This takes water. Water is also needed to make sure the signals from your brain and neurotransmitters are being properly delivered to the sites that you need to balance, coordinate and perform your sport or activity. Water is also needed for over a thousand other functions. As you can see, water is extremely important, and getting dehydrated is the last thing you want to do.
The Vital Nutrient
The water the blood uses to control its volume, transport oxygen and carry nutrients begins to change locations in order to bring things under control. Blood vessels dilate pulling free water out of extra cellular reserves to thin the blood and circulate the needed oxygen and nutrients. Without enough water in your system, the blood thickens and the nutrients of oxygen and fuel the muscles need to satisfy the demands of the work we do. While all these changes are taking place inside, you may notice yourself sweating. The moisture from your perspiration comes in contact with the air and begins to cool you down. That is what is supposed to happen. When you don’t have enough water to supply the demand you need to satisfy normal homeostasis, dehydration begins. Without enough water you will get tired faster, your muscles will get heavier, you may get light headed or begin having difficulty focusing. You may try to blow it off and push through your body’s signals to hydrate but by the time you get thirsty and want your expensive sports drink, your body has used up its reserves trying to adapt.
Even people who don’t exercise shouldn’t rely on thirst to tell them when to take in more water. By the time we start feeling thirsty, slight dehydration has already kicked in. That’s why we should all drink water regularly, even when we’re not thirsty. This is especially important for those over the age of 60. It’s also a good idea to check the color of your urine – a dark or tan color indicates that you may be dehydrated. When exercising, the colder the water the better. Cold water helps to delay fatigue, helping you to work harder in the gym.
You lose approximately 500 to 1000 ml of fluid per hour during a light exercise session which could be about 1 to 2 pounds of bodyweight. During a more rigorous workout in a hotter environment, you could lose 1500 to 3000 ml of fluid in an hour or about 3 to 7.5 pounds of bodyweight.
For decades we’ve been told to drink 8-10 glasses of water per day. The US Food and Nutrition Board of the national research Council now recommends that thirst should dictate water intake. Drinking too much water can lead to water intoxication. This can lead to mental confusion and – in extreme cases – death. A study out of Germany confirmed that we shouldn’t go overboard with our water consumption. It also showed that drinking 2 liters of water per day promotes fat loss. Subjects who took in 2 liters of water each day burned and extra 100 calories per day. That’s the same as running for 15 minutes on the treadmill!
J Clin Endocin Metab, 88: 6015-6019, 2004
Lawrence E. Armstrong. PhD. Bottom Line Health, March 13, 2012