posted on Jul, 30 2006 @ 10:27 AM
Maybe some numbers may help put things in perspective for you.
Our bodies are about 72% water, 8% chemicals and 20% bone and solid tissue(which are mainly carbon and calcium).
An average person sweats out about 0.5 to 1.5 liters a day.
Taking a 15 minute sauna averages at about 1 liter of water sweated out.
The average adult pees about 1.5 liters a day.
So you see that our bodies dispose of 2 to 3 liters of water a day trough sweating and peeing.
When you do sports, this page shows a nice average for how much you sweat per exersize:
From that page: A 10km run at 19 to 24°C ambient will result in about 1.5 to 1.8 liters of sweat lost, depending if your female or male.
Between foods and drinks you need to take in 2 to 3 liters of water a day before your body mass starts loosing water.
[edit on 30/7/06 by thematrix]