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Is the weight of water that you've already drunk that much different from the weight of carried water?
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Marko Botsaris
(millonas) - F - MLife

Locale: Santa Cruz Mountains, CA
Re: Re: Re: Re: Is the weight of water that you've already drunk that much different from the weight of carried water? on 01/22/2014 20:05:29 MST Print View

The end of my taking this type of scatological analysis seriously (ok, I never did) was when Ryan Jordan, about 10 years ago I think, in an interview somewhere argued that if you eat the right food you can cut down on toilet paper carried. I took him to mean at the time something like... ahem... his excrement would have the optimal consistency, rather than constipation, which I suppose would also allow cutting down TP weight.

Anyway, that statement was the hardest core UL one I every heard, then or since. Even though I was more serious at that time about it, I realized I would always be a pathetic amateur, and as such, shouldn't pay any attention.

Edited by millonas on 01/22/2014 20:06:40 MST.

Franco Darioli
(Franco) - M

Locale: Melbourne
Is the weight of water that you've already drunk that much different from the weight of carried water? on 01/22/2014 20:35:10 MST Print View

"i think the term "cameling up" gets used and misused too much. some people that say it think it means like Franco says and think they can "store" water"

I have never seen anyone pretending that we can store up water exactly like camels , as in for days.
If you re-read my comments it should be pretty obvious that I am aware people talk about storing up water for hours.
My point is that if drinking 3 liters or so at once (not an extra pint...) you are just carrying inside you extra weight that is of no use at all, in fact you will end up flashing out salts that your body needs anyway.
There is a balance, but in my opinion the more you get used to drink in one setting the more you will need to drink, just like eating...
To me "tto much is always too much" .
How do I know 3 liters is too much ?
That is another story.

Jake D
(JakeDatc) - F

Locale: Bristol,RI
Re: Is the weight of water that you've already drunk that much different from the weight of carried water? on 01/22/2014 21:01:20 MST Print View

I know you didn't mean for days. I meant that people who use the term can mean different things. some people use it as slang for drinking water at a water source for a drink and nothing more. we can find other slang terms that get thrown around that aren't taken literally unless Bob is your uncle?

i don't drink a lot in general so perhaps i've become used to it. being a cyclist i can only carry 2 x 24oz bottles at a time. I tend to only backpack with 1L unless i know the next source is far enough that i need 2.

i do try to extend that capacity by drinking a bit before i leave, a bit at sources and then rehydrate at camp (or after my rides)

Gary Dunckel
(Zia-Grill-Guy) - MLife

Locale: Boulder
water absorption rate on 01/22/2014 21:12:14 MST Print View

Keep in mind that the average body can only absorb about 1.0 liter per hour from the stomach. The rest just sits there, doing whatever unabsorbed water does. I would rather carry my extra water in a Platy, outside of my body, and then sip it later as needed. But YWCHMV--your water consumption habits may vary.

Mitch Chesney
(MChesney) - F
A study was done... on 01/22/2014 22:44:36 MST Print View

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3351614/

Shows that the half life of water absorption is 11-13min. So if you drink 1L at your rest stop, in about an hour you've more or less absorbed most of it. That being said, 'storing' water in your stomach isn't going to work but it will be stored in your bloodstream unless you overhydrate and piss it out. On the other hand, if you sip your water throughout the day, you're limiting the amount of water absorbed (1 sip = 10ml? so you only absorb 5ml in 11 minutes... kind of a waste of effort). I would (and have!) calculate the amount of water you need per mile or per hour on a given terrain and drink your fill using this 10min half life measurement. It works great on the PCT between water sources... for me it's 1L drunk in one go, walk 4 miles, drink 1L again, and 4 miles later I hit a stream... repeat

Derek Musashe
(dmusashe) - MLife

Locale: Pacific Northwest
Re: A study was done... on 01/22/2014 23:05:47 MST Print View

My general practice is to drink around 0.5 to 1 liter of water if I arrive at a water source and I am thirsty. I simply drink until I feel totally quenched. Then I fill my bottles up with however much water I think I'll need for the next stretch of the hike (before the next water source).

I find that this 0.5 to 1 liter water consumption is just about right for me. It gets me to a point where I'm not thirsty anymore, but it's not so overkill that I feel sick to my stomach afterwards and immediately pee it out.

Everyone is going to have their own preferences, of course, but it sounds like my own practice isn't so far out of line with many other out there.

David Thomas
(DavidinKenai) - MLife

Locale: North Woods. Far North.
Re: Re: A study was done... on 01/23/2014 01:13:07 MST Print View

Rather than relying on intake, I tend to look at output (admittedly easier for pointers than setters).

My MD wife focuses on 30 ml/hour as the minimum output for proper kidney function. You can pass a LOT more water than that, but passing LESS than that indicates you are under-hydrated. So one approach is:

"Could a shot-glass per hour with my pee?" and/or "Did I pee in the last few hours?" If not, drink MORE.

The colorimetry approach is, "Was my urine noticeably yellow/dark?" Then I need to drink more.

The Blood Bank assesses hydration by the tenting of your skin when they pinch the skin on the back of your hand. When I try to change that, it can take 12 to 24 hours of consciously greater input to turn it around.

I monitor urine volume and color for feedback on short-term hydration issues.

I assess skin tenting and my weight (I can estimate my weight to within a pound) for managing longer-term (24-48 hours) hydration issues.

Back to the OP: If you are passing a lot more than 30ml/hour, yes, you could have hydrated less and carried less weight for the previous miles.

Art ...
(asandh) - F
Re: Is the weight of water that you've already drunk that much different from the weight of carried water? on 01/23/2014 10:47:34 MST Print View

the OP's question is precisely why I half seriously suggested in another thread that weight carried should include both the weight of all gear and body weight.
problem solved ...

Dan Durston
(dandydan) - M

Locale: Cascadia
If nothing else... on 01/23/2014 21:01:53 MST Print View

If nothing else, a "camel" approach saves weight in water containers. I don't think anyone is suggesting drinking 3 liters, but by being willing to chug back a liter if needed one can make do with a bit less capacity.

Capacity entails weight, but not much. Maybe an 1-1.5oz saved if you chug a liter instead of packing it. A more salient difference is bulk. If you're packing 5-8 liters in the desert that's a lot of space. I'm heading on the PCT this summer and I want to bring my medium pack (ULA Ohm) rather than my 1 lbs heavier big pack. Drinking water when its available is a small part of keeping my load size manageable.

I think we all agree there's no reason not to drink up within reason, but trying to chug 3 liters is stupid. More important than any of this is carefully planning your water. That means not carrying 4L when you need 6, and it also means not carrying 6 when you need 4. Carefully managing the latter is where appreciable weight savings lie.