How Much Water Do You Really Need When Exercising?

Maintaining proper hydration is a very important part of your exercise program. A little forethought and understanding will go a long way to your finding the most effective way to achieving your personal goals...no matter what they are.

By: Brian Tilley

There has been a lot of seemingly contradictory advice about how much water you need to drink while exercising. Water, per se, is only part of the equation. Of more concern is the loss of electrolytes, primarily sodium and potassium which are critical to the proper functioning of muscle cells in particular.

There is also a difference when you consider gender...women on average need 2.7 liters of water per day, while men need 3.7 liters. These amounts are for a person who is very physically active or who live in hot climates. On average 80% of our water consumption comes from drinking water and beverages, and the other 20% comes from our food.

As far as salt requirements, a healthy 19 to 50 year old requires 1.5 grams of sodium and 2.3 grams of chloride each day...or 3.8 grams of sodium chloride...better known as 'table salt'. This amount will replace the amount lost due to perspiration and to achieve a diet that provides sufficient amounts of other essential nutrients.

High blood pressure, which can lead to a stroke, and coronary heart disease as well as kidney disease, is associated with sodium intake. The maximum intake of sodium that people should consume per day, also known as the 'upper intake level' or UL, is 5.8 grams of salt or 2.3 grams of sodium and 3.5 grams of potassium.

Older people, those with chronic diseases such as hypertension, diabetes, and kidney disease, are particularly susceptible to the blood pressure raising effects of salt and should reduce their intake.

Dehydration resulting from strenuous exercise can seriously impair the body's ability to dissipate excess heat. The heat generated by strenuous exercise is the result from both chemical processes - generating the energy needed to perform the exercise - and the friction of all those muscle fibers rubbing against each other.

To make this issue even more complicated are the reports of people who have consumed too much water - hyponatremia - even some who have died as the result of drinking too much water after exercising.

Fortunately, this problem is actually quite easy to solve. You need to drink as much water as you use. Simply weigh yourself before and after your exercise session and the difference is how much water you used. Another way to gauge this is to listen to your body...it will tell you when you need a drink. If it doesn't tell you it is thirsty, then you are probably OK.

As you age, the 'feeling' of thirst alone may not be accurate. This is why you need to weigh yourself to get a much more objective view of how much water you are using. And don't forget about the electrolytes...you need to keep a balanced intake of sodium and potassium.

The easiest way to do this is with a 'sports' beverage, which are fortified with both sodium and potassium. You need to read the label and factor in the amount of those nutrients into your diet to maintain the correct amount of total salt you consume per day.

To sum it all up...listen to your body and consume the amount of water you need. Everybody is unique and will need a slightly different amount of water from others, as well as a different amount determined on how strenuous the exercise is and what the ambient conditions are - humidity and temperature.

Maintaining proper hydration is a very important part of your exercise program. A little forethought and understanding will go a long way to your finding the most effective way to achieving your personal goals...no matter what they are.