Training from the mile to the marathon.
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  • What do you mean when you talk about hydrating?

    Posted on June 15th, 2009 CoachGreg 1 comment



    What do you mean when you talk about hydrating? How much should I be drinking? What should I drink?


    Summer in the lowcountry is tough on marathon runners. Dehydration is when the water in your tissues is depleted below normal levels. Your performance is affected when you lose as little as 1% of your body weight. For a 150 lb man, that’s 1.5 lbs.

    Water is absolutely your best fluid to combat dehydration. The best way to tell if you’re dehydrated is to check your urine color. Here’s a good explanation of what to look for. Scroll down to see the urine color chart. (Yes, Boot Campers, I know it’s from the Army but it really is good information.)

    You can come up with a rough gauge to estimate how much you should be drinking by doing a simple sweat test.

    1. Weigh yourself with no clothes.
    2. Get dressed.
    3. Run for an hour or whatever kind of exercise your normally do.
    4. Weigh yourself again with no clothes after completely toweling off.

    If you drink anything between the weigh-ins, then you need to measure what you drank. Your weight in ounces that you lost is equal to your sweat rate in ounces/hour for that type of exercise and exercise conditions. In my case, my sweat rate for running in the middle of summer is at least 64 ounces/hour. ┬áIn Boot Camp, it’s about 30 ounces/hour when we’re indoors in the winter.

    What about sports drinks?

    Sports drinks contain lots of sugar and are useful for staying fueled during a long run but for now, stick to water. That’s what they were developed for. We’ll talk more about fueling at a later time.

    How Much Should I Drink?

    It’s not really complicated. I try to make sure I am fully hydrated before I go to bed and I drink 16-20 ounces first thing in the morning to replace what I’ve respired out overnight. During the summer, I am really vigilant about drinking water in the evening and I don’t really care if I need to use the bathroom multiple times in the middle of the night. Better that than to be dehydrated when I start out in the morning.

    I try to consume at least 28 ounces of water an hour while running if I’m running more than 90 minutes. That’s what most sources claim to be the maximum amount your body can process in that hour. After I run, I consume at least one ounce for every minute I was exercising because my sweat rate is approximately 1 oz every minute. I try to do that within the first hour after I’m done and I’ve been known to completely consume two 24 ounces bottles immediately after running.

    Coach, I have one more question: I’ve heard that cold water will cool me off quicker than tepid water. Is that true?

    Yes - but not so you would notice. The cooling effect is very minimal. However, if having your drinks cold will induce you to drink more and more often, than drink cold drinks.

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