I am currently training for a marathon. Due to a change in my schedule starting Dec 1, mornings will be the only time I can run. I heard that it takes about an hour for the body to absorb water, so currently on weekends I drink 24oz of water right when I wake up, urinate, then go run. However, on the weekdays this doesn't seem so feasible:

Wake up -> Drink water -> wait an hour -> run 10 miles -> shower/eat -> drive to work

Seems like an extremely early morning. Is there any way to make it better? Is it really necessary to wait a whole hour after drinking water?

  • 2
    Have you tried running without the waiting?
    – Baarn
    Nov 29, 2012 at 15:04
  • Why do you drink water before you run?
    – user4644
    Nov 29, 2012 at 22:39
  • You drink water, preferably with some salts and glucose, to last longer, @Kate.
    – user5279
    Feb 21, 2013 at 20:45
  • @George No I don't. I just stay generally well hydrated, and don't drink extra water before runs. Also, my question was why clavio drinks water before he/she runs.
    – user4644
    Feb 21, 2013 at 22:05
  • 1
    @George, I was trying to get clavio to clarify his/her motivation for drinking water before runs because I suspected it was incorrect. johnp anticipated this and gave an answer I agree with.
    – user4644
    Feb 21, 2013 at 22:31

3 Answers 3


Whether or not it is necessary to wait an hour depends on you, actually. Some people can drink a lot and go run, some people can't.

However, unless you are chronically dehydrated or exercising in extreme weather conditions, you won't need water for most of your runs. You should be getting most of your hydration from your diet during the course of the day, and there isn't really a need to drink 24 oz. as soon as you wake up. On a personal note, unless I am running in 100+ degrees (Phoenix in the summer), I don't need to drink/take water on runs up to 12ish miles (1 hour 30 mins or so). Anything beyond that, I bring about 20 oz of fluid with me and sip along the way.

The "8 glasses" is a bit of a myth. Yes, the body needs that much fluid, plus some extra for exercisers, but the majority of that will/should come from your diet. When the Western world started eating less and less fruits/veggies (A high source of fluid), dieticians came up with the 8 glasses to ensure adequate hydration.

Weigh yourself, go run, and weigh yourself when you get back. Aside from glycogen losses, you'll need about 8-16 oz extra throughout the day for every pound lost.

Most people way overhydrate when they exercise, as can be seen by the people that are chugging a gallon of water during a 1 hour weightlifting workout. Not really necessary, replace after and eat a healthy diet with fruits/veggies and you should be fine.

  • 1
    I will try not drinking water before my next run and see how it goes.
    – clavio
    Nov 29, 2012 at 16:17
  • @ngramsky 's answer seems important here. "You do dehydrate as you sleep ... so I'd reco keeping a glass on your nightstand to drink the moment you wake up in the morning. You don't need the entire 24oz, a simple 4-8oz will do"
    – nilon
    Sep 4, 2023 at 4:24

I don't mean this so much as a definitive answer so much an anecdotal one.

A few years ago I discovered that my morning run times were measurably better, and I FELT much better, if I drank a whole liter of water right before bed. I continue to do this when I plan on running the following morning.


To add to the two previous answers alerady...

Hydration as a WHOLE needs to be addressed more so than the hydration one understakes right before running. One should be adaquately hydrated in general.

You do dehydrate as you sleep though through breathing (especially in the winter when the air can be dry) and sweat. You could also drink a less amount of water (24oz. is a lot IMO) as you wake up. You should give yourself a few minutes to stretch, losen up and wake up before heading out the door anyway, so I'd reco keeping a glass on your nightstand to drink the moment you wake up in the morning. You don't need the entire 24oz, a simple 4-8oz will do quite a bit I believe.

I tend to keep a glass of water on my nightstand and, anytime I wake up in the night, I grab it for a quick drink.

Lastly if your body needs a lot of hydration you could always drink water DURING your run. If you are running a marathon you shoudl practice drinking during the run. These early morning runs can be a great time to do so if you must hydrate a lot for any run.

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