1. Do drink beforehand. Make sure you are well-hydrated leading up to a long run or race (monitor the color of your urine to make sure it’s pale). And on the day of the run/race, try to drink about 16-24 ounces of water about an hour beforehand. If you keep drinking right up to race time, you may experience one too many bathroom breaks during the workout/event.
2. Do monitor your intake. During your run, some suggest 4-6 fluid ounces of water every 20 minutes, others recommend 6-12 ounces every 15-20 minutes. Experiment with how much is the right amount for you. Are you currently drinking less than either of these recommendations?
3. Don’t wait till it’s too late. If you’re thirsty, you may already be dehydrated. Your performance will decline if you don’t consume adequate fluids, so nip that problem in the bud before it happens. And don’t forget to drink early in the run, when you won’t likely be thirsty.
4. Don’t assume everyone’s alike. Generally speaking, the more fit you are, the more efficiently your body uses water. Variations in size, gender, age, and metabolism also influence the amount of water you need and use.
5. Don’t ignore the weather. If it’s really hot or you’re high in elevation, you may need more water than normal.
6. Don’t just drink water. Most agree that at the 90 minute mark, it’s time to incorporate sports drinks into the mix. Sport drinks replace sodium and electrolytes that a person naturally loses during a long workout, so you may avoid cramping and nausea by replacing them. But also consider what you are eating, and alter your choice of beverage accordingly.
7. Do sweat it. The amount you sweat will also determine how much water you need. You can weigh yourself before and after a long run to see how much fluids you typically lose during the course of a workout. One pound of weight loss equals 1 pint of water loss. And you need to replace what you lose.
8. Don’t ignore the signs of dehydration. These are chills, dizziness, disorientation, and cessation of sweating. If you start experiencing these, don’t panic. Instead, stop running, find a cool spot and start drinking!
9. Don’t drink too much, either. If you feel fluids sloshing around in your belly, it may be telling you to ease up a bit. In the extreme situation, you might experience hyponatremia. This is when you consume too much water and not enough salt. Symptoms include: confusion, disorientation, muscle weakness, and vomiting. You can prevent this problem by drinking sports drinks (in addition to water) and/or eating salt.
10. Do hydrate afterwards. The recommendation is to drink 20-24 ounces of water for every pound that you lose during the workout. Recovery drinks with carbs and protein may also be beneficial in improving the way you feel the next day. And of course, after you have properly recovered, I see nothing wrong with a celebratory beverage!