The average person can lose 2-3 liters of water a day just through activities of daily living, not including the added loss from exercise. During intense exercise, water loss can be as much as 2 liters/hour.  Obviously the amount of water lost each day will vary from person to person, due primarily to differences in resting metabolic rate and amount of activity. It’s easy to understand why, at a minimum, we should consume at least 2 liters of water every day, more if we’re quite active.


We can’t depend on our sense of thirst to tell us when we need water. By the time we’re thirsty, we’re already somewhat dehydrated. So, drinking water just needs to become a habit. Drink before you get thirsty.


The following recommendations are for water intake in relation to an exercise session. 


Time                                                    Quantity (cups)

2 hours before                                        2 to 3+

15 minutes before                                  1 to 2 

Every 5-10 minutes during                   ½ to 1


Cannot over-emphasize the importance of drinking plenty of water in the ½ hour to hour after exercise.  Remember to consume at most a cup or two at a time because that allows more of the water to move from the bloodstream into the cells. 

  • Drinking 4 cups at once causes the blood level to rise so rapidly the kidneys will filter out more than they will with small "doses." 

 

Drink your water, not only during your exercise, but after as well!  Replenishing your fluids is very important and should not be ignored.  


A common recommendation is to drink six or eight 8-ounce glasses of water or other fluid every day. But some adults may need more or less, depending on how healthy they are, how much they exercise, and how hot and dry the climate is.

You may sometimes need to drink more water than usual if you: