Another weird question - this time it's biology/human physiology

[seedjar]

So, I've got to run for the bus but here's the question - how much water does the average human body transpire on a daily basis? (High/lows and the body sizes they're calculated at would be even better.) I guess I'm looking for respiratory transpiration and sweat, if you have mixed data to offer.
Thank you all in advance for entertaining (and tolerating) my inane queries.
~Joe

 

[dashman]

I realized you asked for average, but my guess would be that this would vary depending on metabolism. Persons with higher metabolism and/or a more active lifestyle would utilize more water througout the day than a more sedentary person.

I can attest to that. Way back when I played football, we had to weigh ourselves before and after each practice so that the trainer could monitor our body mass and water loss. I once lost 11 pounds in a single 2 1/2 hour practice. I weighed in the 180's at the time. The trainer sent me home with two bottles of electrolyte drinks that I had to drink that night.

 

[seedjar]

Finding statistics for water loss in general isn't that hard. But figures on how much of that goes to transpiration rather than diaphoresis and elimination don't seem to be as readily available. Or maybe they are, and I just don't know what keywords to search on. Google really isn't very good at sorting academic papers.
~Joe

 

[Not a Number]

Try google scholar
http://scholar.google.com/scholar?q=human+transpiration

 

[seedjar]

LOL - I hadn't looked before, but that's even worse than the generic results I get. Google Scholar has appealed to me since it was first released, but I don't think I've ever found anything really useful from it. I probably don't know enough buzzwords for the fields I'm searching.
~Joe

 

[swords]

I can't help you with averages but I know you don't let go of as much water if you have heart trouble. My old man can't have very much salt or his body will lock up all the water he drinks and he'll basically become like a water balloon.

 

[chezilla]

The term is "insensible" water loss. It is the normally unmeasurable amount of fluid lost from sweating and breathing. The average minimum amount is 500-800 cc/day. I have seen some MD's use 50 cc/hr for hospitalized (physically stressed) patients. This increases with higher temps (body and environment), exercise, elevated heart rate and resp rate, excess speaking, etc... For healthy adults the amount of water "created" through metabolic processes is roughly equal to insensible loss so it is not usually factored in when doing intake /outputs. The normal exceptions are surgical patients, burn patients, ventilator patients and new borns.

 

[seedjar]

You're awesome, chezilla. That's exactly the word I needed. Damn these ivory-tower medical ontologies!
~Joe

 

[thez_yo]

All of the survival experts I've talked to say to pack a minimum of a gallon of water per person per day, in the event of some sort of emergency/evac. I'm not sure if they mean for everything (washing hands, etc.), or just for drinking water.