How to: Hydration and fueling when running
With the high temperatures and humidity, it is extremely important to stay hydrated and replace any lost fluids when doing any type of exercise outside, especially running. In addition to drinking water, it is very important to replace electrolytes, which I see a lot of runners neglect.
Electrolytes (which are comprised of sodium, potassium, calcium, magnesium, chloride, phosphate, bicarbonate, and sulfate) are important because they affect the amount of water in your blood, the acidity of your blood and other bodily functions.
How do you know if your electrolyte levels need to be replenished? Some common symptoms of low electrolytes are muscle and stomach cramping, as well as side stitches. Typically, resting and consuming electrolytes will make these symptoms go away. Symptoms of dangerously low levels of electrolytes include dizziness, muscle spasms or total loss of muscle control, headache, confusion, extreme fatigue, nausea, constipation, and dark urine. If you experience any of these later symptoms, stop whatever you are doing and seek medical attention.
Electrolytes sweat out of the body and cannot be replaced by water alone. In fact, there have been extreme cases where runners and other athletes suffered or died from water intoxication because they drank too much water that diluted the remaining electrolytes in their body.
The good news is that there are a wide-variety of means to replace electrolytes. The old standby of Gatorade works great (though it has a sugar in it). Coconut water also is a good source of electrolytes (less sugar, though about 2-3 times more expensive than a comparable-sized sports drink). Most well managed road races nowadays have Gatorade or another sports drink at water stops along the course.
Another option is what are called "energy food products" such as Gu, Sports Beans, etc. that you can carry with you and take as needed. Not only do they have electrolytes in them, but also carbohydrates, which your body uses as fuel. I personally like the Sports Beans as they come in a resealable pouch that I can keep in my pocket when running. (For long runs, I usually take one pack about a half hour before the start of a race and then another pack every 45 minutes.)
As with any type of running gear, it is best to test out before a race how your body will react to your electrolyte fueling strategy and how well you can digest them. Don't find out during a marathon that you stomach doesn't like the product you have chosen!
Here are some general guidelines to follow on when to rehydrate, refuel, and replace your electrolytes:
Less than one hour (i.e. 5k, 5 Miler, 10k)
No additional food or carbohydrates are necessary.
You should drink 4-8 ozs of fluid every 15-20 minutes or 16-20 ozs per hour (water is fine).
90 minutes – 4 hours (i.e. 10k, Broad Street Run, Half Marathon, Marathon)
You should be replacing about 300 calories/hour using a sports drink or a gel (such as GU, Sport Beans, etc.)
You should be drinking at least 20 ozs of fluid an hour. Be sure that some of the fluid contains electrolytes.
4 – 12 hours (i.e. Marathon, Triathlon, Ultra Distance Running)
You should be replacing about 300 calories/hour using a sports drink or a gel (such as GU, Sport Beans, etc.)
You should be drinking at least 20 ozs of fluid an hour.
You should be consuming at least 500 – 2,000 mg of electrolytes an hour
12 – 18 hours (i.e. Triathlon, Ultra Distance Running)
You should be replacing about 300-600 calories/hour with about 60% of it carbohydrates, 20-30% fat, 10-15% protein.
You should be drinking at least 20 ozs of fluid an hour.
You should be consuming at least 500 – 2,000 mg of electrolytes an hour
Potassium should be replaced at the rate of once every 3-4 hours
David Wisniewski is a CrossFit Endurance certified running coach at Philadelphia Running Concepts and has been training runners of all levels and abilities. More information can be found out at phillyruns.com.
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