Running and Hydration — Water is key to your natural cooling system.

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In the past days of simple running, like to during “Chariots of Fire,”  running used to be uncomplicated and simple.  You just put on your shit, shorts, and shoes and went running.  What!  No water?  Yep, no water…

Drinking (or hydration) was not such a big deal before, but, collectively we’ve grown wiser and now understand the importance proper hydration contributes to both our health, safety, and overall running performance.

What is Hydration and dehydration?

Our bodies have many uses for water and are made up of somewhere near 60 % of our weight.  One of the uses is to cool the body through perspiration.  But this causes us to loose water, and since our bodies must maintain its balance in water, or our body chemistry goes out-of-whack, we must be sure to properly hydrate before, during, and after running to compensate for this loss.

Severe dehydration (loss of water) and over-hydration both cause serious consequences on the body, including death. Knowing the difference is sometimes hard because the symptoms are the same.

Caution!  Overhydration and Dehydration have Similar symptoms

In dehydration, the symptoms include weight loss, lethargy, dizziness, nausea, vomiting, confusion and dry mouth or lips. Over-hydration includes weight gain or swelling, headache, nausea, lethargy and confusion or disorientation.  I found this interesting as I’ve been experiencing headaches after running.

What is terrible is that nobody knows about the problem until the symptoms are already in the advanced state. Even medical personnel can be hard put in figuring out what exactly is happening. (This usually happens after a hard race.)

I always thought it was because I wasn’t drinking enough water, but perhaps I’m drinking too much.  I’m going to start monitoring my water loos, by weighing my self before and after running (see below) to get a better handle on my fluid loss.

Calculate Your Fluid needs

Drink Water When You Run

Knowing how much fluid you need can prevent either dehydration or over-hydration. One way of knowing is that your performance will decrease significantly if you are dehydrated by as little as 1%.

Your running slows down by about 2% if you are dehydrated by only 1%. Another point to consider is that hydration is important not just for your performance but also for your health. As a runner, you need to know how much you need to hydrate yourself daily, and in the critical times of before, during and after running or a race.

One formula given by experts to calculate your daily fluid needs is as follows: multiply your weight (in pounds) by 0.55 to know how many ounces of fluid you need every day.

You can find out how much fluid you’ve lost during a run by weighing yourself before, and after your run.  Here is the data you’ll want to collect:

Here is the Calculation:

  • Temperature;
  • Humidity
  • Weight Start of Run (A)
  • Weight End of Run (B):
  • Weight Loss (B) – (A) = (D):
  • Water Consumed During Run in Ounces (E):
  • Ounces Water Perspired: (D) x 16 ounces/pound + (E)

Before your run, weight yourself without any clothes on, then after your run do the same.  You want to do this because after your run, your clothes will be soaked, and we don’t want to include that as  part of your body weight.  Also keep track of how much water you have put into your system.

Since there are about 16 ounces of water in a pound, we know that for every pound you loose during your run, you have expired 16 ounces.  Add to this the amount you drank, and we arrive at how much fluid you  lost during your run.

Since we loose more or less fluids according to temperature and humidity, it is good to track those measurements.  As you build up a history of measurements, you’ll be able to construct a profile over a variety of conditions.

Here is an example from one of my runs last September:

  • Temp:  63
  • Humidity: 61
  • Loss: 7 lbs
  • Water During Run: 20oz
  • Oz Perspired: 7*16+20 = 132
  • Length: 12 miles
  • Duration: 139
  • Oz/Minute: .95

I found it surprising that my body consumed or lost almost one ounce of water a minute.  When I realized this, it really made start to look at water a consumable just as food or calories are.

So What Are Good Fluids to Hydrate you System?

Good beverages include water , sports drinks, tea, decaf coffee, low fat milk, yogurt drinks, juices, soda and soups or other foods with water.  Water, of course, is the best source for body hydration. Intake of beverages with sugar and other additives should be limited, especially if you are trying to lose body fat.

I typically drink water, and supplement with sports drinks or GU, during long runs, to maintain electrolyte levels.

Alcohol is one drink that significantly dehydrates the body. It is a total no-no to drink before races, or even the night before any race.

Before You Run

Before you run make sure you’re adequately hydrated.  Make sure you start running the right way.  Before a long run or race, I’ll like to prepare by drinking lots of water the day before, say at least ten eight ounce glasses.  I stop drinking water two hours before my run to let my stomach settle. Be prepared, either carry or cache water for long runs.  I use a belt and can carry up to forty ounces if need be.  During the warmer months, when my water won’t freeze, I place water bottle along my long routes the night before.

For shorter runs I carry a hand bottle.

After I run I’m sure to drink enough fluids to replace what I lost.  Sometime it can take up to a half day for that to happen.

How do you keep hydrated while running?  Do you have any tricks you us before or after to help you ensure you’re adequately hydrated?


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