I am curious about some techniques/guidelines for achieving and maintaining optimal hydration while performing moderate to high strain outdoor activities, such as long hikes etc. IOW, how do you hydrate yourself JUST ENOUGH, not too much, not too little.

The reason that I am asking is that I noticed that, when not sweating too much and not peeing, I don't need too much water. Excessive water intake causes more urination, which means you have to make more frequent stops and also your organism "learns" to use more water, i.e. gets adjusted. So I am thinking there could be techniques for optimal and balanced hydration that do not rely simply on thirst or a pre set water intake schedule and instead is perhaps a function of drinking water only after urination and in the amount that is approximately commensurate to the amount of urine.

  • 3
    This whole topic is shrouded in urban folklore. One type of useful answer is the one Jonathan Patt: drink when you're thirsty. The only other type of useful answer I can imagine would be an evidence-based one, e.g., from some kind of controlled scientific study. Unless someone comes up with something like that, I think you're just going to get a lot of personal opinions that are not based on any objective evidence.
    – user2169
    Commented Sep 14, 2015 at 23:42
  • 1
    @BenCrowell Karen's answer and my own may be phrased as a first-person anecdotal stuff; but professional trainers will often recommend the same stuff we're writing down here.
    – Roflo
    Commented Sep 15, 2015 at 14:18
  • 1
    @BenCrowell: Like yourself, I prefer a bit of science with my water. Conventional wisdom/opinions may fall a bit flat here. If we're talking water absorption vs fluid turnover rates (i.e.: how much of the water you're drinking actually gets used), there's a study about it here. Short version: Camel up every few miles or half hour (assuming you're a semi-fit adult and the trek isn't overly difficult).
    – Zach L
    Commented Sep 15, 2015 at 17:47

5 Answers 5


The absolute best way to figure out when to drink is by paying attention to your thirst.

If you drink a cup of water when you aren't really thirsty, your body will start getting rid of excess fluid within a few minutes. But if you drink that same cup when you are seriously dehydrated, you won't pee it out because your body won't have excessive moisture. This is all related to how much fluid is in your body, not the time since your last urination.

If you want to avoid peeing any more than you have to, get very, very familiar with how you feel when you are just slightly dehydrated (a tiny bit thirsty, but not excessively so, and certainly not unpleasantly so). Then drink small amounts frequently when you start feeling that way. Have a couple of swallows: that will momentarily slake your thirst. Then if you are thirsty again in 5 minutes, repeat this. If you drink large amounts, you are more likely to drink enough to completely rehydrate completely, and need to pee again. It will take experimentation to figure out exactly how much you need to drink, and what you should feel like, but once you do, it's quite reliable.

If you are trying this, and don't drink enough, you can get seriously dehydrated, especially if you are sweating a lot. So be cautious when you are starting out, and err on the side of drinking more. Also, at the end of the day, it's a good idea to rehydrate completely, both for your own comfort, and because urination is very important for the body to rid itself of toxins.

  • 2
    Paying attention to your thirst is not adequate in a physically stressful environment. You may drink too much, or you may drink too late, or both. In fact, when you push yourself really hard and don't keep up with the necessary water intake, your body may stop processing food and water in your stomach for a while, resulting in nausea and often vomiting. This is relatively common for people not acclimated to high altitudes.
    – xpda
    Commented Sep 15, 2015 at 2:51
  • 8
    xpda: paying attention to your thirst is fine, it's a biological control with half a billion years of development. Commented Sep 15, 2015 at 3:29
  • 3
    @xpda The problems you're talking about are normally because people ignore the early warning signs that they feel like shit, and try pushing through. That sort of problem can usually be prevented by paying close attention to what your body is saying. Athletes train themselves to ignore these cues, and that gets them in trouble if they are suddenly in a situation very different than what they are used to, like high elevation or extreme heat.
    – Karen
    Commented Sep 15, 2015 at 13:11
  • when exerting yourself (such as a step climb in high sun), you can sweat more water than you can absorb by drinking. In which case you need to drink before, during, after.
    – njzk2
    Commented Oct 22, 2015 at 15:42

I don't usually care too much about making a pee stop if I'm hiking (I just don't mind). In the last couple of years, however, I've taken on running and have since ran a marathon and a handful of half-marathons (and a one-minute pee break is a lot when you're trying to beat your own record).

Pro-advice for hydration usually falls under two big categories:

  • Drink when you're thirsty
  • Measure your liquid loss

And that's good advice to stay hydrated, but offers little insight into optimizing urination stops.

My races so far have taught me quite a bit about how my hydration works. I stress that it's my hydration because I've seen that it works differently for different people, so YMMV. Nonetheless, these are a few tips that may work for you. Many of these tips are often recommended by some professional trainers and long-time athletes:

  • Try taking a sip every five-to-fifteen minutes during exercise instead of a big gulp every hour. If it's still too much water, try just wetting your lips or taking a smaller sip.
  • I found out that starting my workout very well hydrated is key to staying hydrated. I usually drink abundant water about one hour before starting my workout.
  • Just before starting my workout I avoid drinking too much water (a few big gulps at the most).
  • If you have enough water at your disposal (common in races, not quite so if hiking) wetting your head may help you sweat less by helping your body regulate temperature.
  • If I start perceiving (smelling) my own sweat (or a dry mouth, as other have pointed out), it's usually a sign that I need more hydration. I'll usually compensate by taking one gulp right then and there while making sure my sips are a bit larger.
  • If you expect to exercise for more than an hour or two, plain water might not be enough. If your average sport drinks have too much sugar for your taste, try drink tabs.
  • Keep in mind that at some point your body will need to pee (it's not just to discard excess water). So depending on how long your "long hike" is, you're gonna need to make a stop.

Again, you're gonna have to try it out for yourself and figure what works for you.


Drink when you're thirsty, don't when you aren't.

  • 1
    This does not provide an answer to the question. To critique or request clarification from an author, leave a comment below their post.
    – ppl
    Commented Sep 14, 2015 at 20:23
  • 1
    @ppl Yes, it does provide an answer to the question. Your body has a highly accurate understanding of its hydration level and it shows that by making you thirsty when you need to drink water. Since everyone's requirements are going to be different, listening to your body is the best approach. Commented Sep 14, 2015 at 23:42
  • @JonathanPatt that comment was auto-generated by SO. Typically we benefit more from more elaborated answers. i.e. one-liners are discouraged and sometimes preferred as a comment instead of a standalone answer. If the answer gets upvoted I can simply delete those comments and move on. :) Cheers!
    – ppl
    Commented Sep 15, 2015 at 0:03
  • 4
    Sometimes nothing more needs to be said. Commented Sep 15, 2015 at 1:35
  • 1
    Sorry, I don't agree. The OP is specifically asking for techniques for optimal and balanced hydration that do not rely simply on thirst. It's a good answer, just not what the OP asked for.
    – Roflo
    Commented Sep 15, 2015 at 14:03

Too much water is better than too little. It's a good idea to drink before you're thirsty if you know you're going to need it. You can guess how much, and then drink more or less depending on the frequency of urination. Higher altitude, warm weather, and physical exertion all cause more water loss, so you need to drink more. As you get dehydrated, your mouth gets dry, you stop urinating, and you may get a headache.

  • 1
    Too much water can be bad, actually, if you drink too much and this lowers the electrolyte levels in your blood, this can lead to severe cramps, and inhibit your bodies ability to use the water, etc. This is why isotonic drinks include salt(s). Drinking before your thirsty is likely a bad idea too. Thirst is your bodies way of telling you, you need water, if you drink before your thirsty then your countermanding your own bodies systems to regulate itself.
    – user2766
    Commented Sep 17, 2015 at 7:42
  • ...I've seen people abandon long hikes due to cramp, it's not necessarily something to be trifled with
    – user2766
    Commented Sep 17, 2015 at 7:48
  • 1
    You are incorrect, Liam. In a hard hike, especially in the heat or at high altitude, it is common to lose water faster than your body realizes and makes you feel thirsty. If you don't keep on top of it, you WILL become dehydrated. If it's a leisurely hike with little physical exertion, then it's is not a problem. backpacker.com/skills/…
    – xpda
    Commented Sep 17, 2015 at 14:53

I honestly go on intuition and avoid taking big gulps. If you are chugging water and not obviously sweating or in serious heat-casualty conditions, then you are likely not drinking enough water to keep up with your activity level or environment, or you are over-drinking, in general. By keeping water a casual thing, it tends to discipline when you drink it. Snow conditions and deserts would be exceptions because you probably will need more than you think. I have to forcibly remind myself to drink in extreme cold because I don't notice as intuitively how dry the air is.
Obviously, if you are really pushing yourself physically or in severe heat conditions, chugging might be necessary. This method helps me, at least.

  • 1
    I'm not sure what your second sentence means. Can you edit it to make it clearer?
    – ab2
    Commented Sep 14, 2015 at 20:34

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.