View Full Version : How much water?

10-08-2017, 19:02
I'm curious how much water people drink on the trail. I know the temp has a lot to do with it but is there a minimum amount per mile or something that you guys use as a rule of thumb. I ask this because I hiked on the Foothills Trail last November during a hot spell and I was dehydrated after a day and half and cut my trip short. I thought I was drinking enough but it was really hot.

10-08-2017, 19:13
As you say it depends.

Most of the time, 1L per 5 miles is a fair avg, and 4 L per day.
If hotter, maybe 1L per 3 miles
When its really hot and uphill...1L per mile isnt out of the question.

I have hiked 10 miles with no water many times if its reasonably cool or non-strenuous.
Once, I hiked 15 miles drinking only about 2" in bottom of liter bottle.

Ive run 10 miles in 95F and high humidity without water a few times too.

So, it just depends. On weather, terrain, and necessity.
I drink a lot at camp in evening. Usually 1L with dinner, which also contains about a pint.
I have drank as much as 2L before after stopping for evening, and only peed out about a pint overnight. Dehydrated...yeah.
I dont particularly worry about it. When my saliva is thick, or the trail starts seeming harder than it should, I know Im dehydrated. Or, If I get confused and start second guessing the map.....thats a bad sign. Been there.

10-08-2017, 19:47
As MuddyWaters said, it depends. Between 2 and 4 liters is fairly typical. As long as I’m occasionally peeing, I’m good.

10-08-2017, 20:09
It is important to stay hydrated, but you can over hydrate as well. Over hydration happens when your sodium and water levels are out of balance. Can result in swelling most noticeably in the hands.

10-08-2017, 20:22
Everyone has different water intake needs. Those needs change based on exertion and weather. I can go 10 miles and drink a liter, or go one mile and drink a liter. It just depends. I drink when I get thirsty and don’t really think about how much it is. I do notice if I am drinking significantly more than usual though.

I normally start a trip with 2 full 1 liter bottles of Gatorade, and then refill only enough to get me to the next water source after I drink the Gatorade. If I run out early, I know it won’t really matter. Drought conditions are a little different, and I usually am carrying a minimum of 1 liter at all times just in case the next sources are dry.

As MuddyWaters said, you can hike for a good while without water as long as you can replenish it later.

10-08-2017, 21:15
As needed. Definitely depends on temperature, effort expended, etc. Hot summer day with typical AT verticals, easily three quarts per day.

10-08-2017, 22:53
Mostly I drink when I'm thirsty, and don't worry about the amount. The first exception is at water supply points, where on a hot day I'll drink until I'm full. Then back on the trail I'll drink when thirsty. The second exception is at bedtime, where I'll empty my bladder and then drink a pint of water whether I'm thirsty or not. I've found from experience that that keeps me from waking up from thirst in the night, and my bladder capacity is adequate to keep from waking me up early (most of the time) from too much liquid.

Leo L.
10-09-2017, 04:42
My body tells me when it needs water, I simply drink when I'm thirsty.
As an old habit from my desert hikes, I pay some attention to peeing - frequency, amount and color.
Another old desert habit is, that I refill my small drinking bottle at every source (spring) I pass by.
In the evening I drink just enough to feel well, but in the morning I usually drink a good amount.
For longer dry stretches I know about ahead, I will camel up as much as possible, and some more.

10-09-2017, 05:15
I mostly drink when thirsty, but it's not nearly enough. I may not feel all that thirsty, but when I'm sweating heavily and pee volume is just a trickle, that's a clear sign that I need to hydrate much better.
Physical exertion = wear & tear = cellular waste products = need high water input to flush system.
When I am dehydrated, I'm hurting myself. :(

10-09-2017, 07:29
Ditto the first couple of posts. At a minimum on a temperate day, one liter per ten miles is baseline. (The engineer in me hates mixing unit systems, but that seems to be okay here.) Double or triple that as needed.

When there's a dry camp involved, you need to know your camping requirements too. That varies from 1/2 to 2 liters per night.

On a day hike, it completely depends on what you ate and drank the day before (if you had pizza and beer vs. brown rice and tea or something awful like that).

Pay attention to what you need and start developing your own equations.

10-09-2017, 07:34
It is important to stay hydrated, but you can over hydrate as well. Over hydration happens when your sodium and water levels are out of balance. Can result in swelling most noticeably in the hands.

I think that's called hyponatremia. Another symptom, though it may be too late when you notice it, is your sweat feels very slick--no salt in it. A guy I know told me that's the last thing he noticed before waking up from a coma a few days later.

I can gauge my salt levels by how salty backpacking food tastes. If I find myself adding the whole flavor package to the Ramen and it tastes okay, I know I really need the salt. On hot days, I add salt until the food tastes salty.

10-09-2017, 07:58
I can gauge my salt levels by how salty backpacking food tastes. If I find myself adding the whole flavor package to the Ramen and it tastes okay, I know I really need the salt.
With most Ramen flavors this is a pretty good metric; using the whole flavor packet is usually too much salt. Note that some flavors don't follow this rule. An example is Sriracha Chicken, where the whole flavor packet may be too peppery for some tastes, but probably not too salty.

10-09-2017, 08:47
A prior poster mentioned a salt imbalance, its more than that, its electrolyte imbalance which is more than salt. Potassium is also a big one. Unfortunately there isn't a distinct clue from the body that electrolytes are getting low until the headaches, mental confusion and cramps kick in. I used to supplement salt and still would get late night leg cramps after a long hike, once I added potassium they stopped. Bananas as a good source of Potassium along with a lot of other natural sources, a local chain of gas stations in Northern New England sells bananas for cheap and I usually pick one up for the ride home from a hike.

When I am running long group hikes, if anyone starts getting quiet and is getting a headache I usually get them to use a Nuun and add it to a quart of water and they usually see an improvement in 15 or 20 minutes. I use an electrolyte supplement when hiking and find that I drink less water then when I am not using it. Unfortunately most folks keep drinking straight water which further flushes out electrolytes and increases their thirst. I use Nuun for convenience and lack of sugar but a teaspoon of morton's lite salt (which contains a mix of salt and potassium) per quart of water with enough flavoring to cover the salt taste works as well. Many of the sports drinks have way to much sugar, the standard recommendation is dilute it with water 100% (one part gatoraide to one part water). Alternatively Pedialyte is basically the same stuff.

Leo L.
10-09-2017, 08:55
Thats what we use Cube Soup for.
Not many times in use, but I carry one on every desert hike.

10-09-2017, 09:29
I believe in high hydration even during non hiking days and try to drink at least 100 oz of water on days when I don't work out and then 160 oz on days when I do a cardio session. I add electrolytes to a few of these bottles or take an electrolyte chewable tablet. On days I hike I take an additional sports supplement (salt/potassium/magnesium, etc.) in the morning (x 1.5 doses) and this has fixed a terrible cramping problem I was having.

When it is hot, I am probably drinking 1L every 2-3 miles with nuun or similar tablets and am sure to be well hydrated to start the day and as I begin after rest stops.

10-09-2017, 13:10
It's best to carry too much until you've figured out what you consume in different conditions. It really sucks hauling up hill in the heat for 2 hours while rationing 3 oz of water.

If it's cool and I'm going flat/moderal terrain or downhill... I need very little over 10 miles.
But certain conditions can make me need like 4 litres over 10 miles. I sweat a ridiculous amount in the heat as well.

10-09-2017, 14:17
1L every 5 miles in 70-80 degree weather on AT in Virginia. .5 to 1L for an average Breakfast, lunch, or dinner break.

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10-09-2017, 17:27
I usually never drink enough water, I don't know how because I feel like i'm constantly drinking all the time, but I barely pee all day. then the end of the day I drink probably over a gallon then pee a lot until I go to sleep. I would say I should be drinking at least 2.5 liters for every 10 miles to not be dehydrated but that rarely happens