Runner's Web and Triathlete's Web Article on Dehydration

Your body is over 60% water and that means that if you exercise while dehydrated you reduce your performance and increase the risk of injury - including running cramp.

Some tips on hydration:
* Start your exercise well hydrated
* Have a hydration plan for before, during and after an event.
* Drink before you feel thirsty - when you're thirst it's generally too late.

Water loss from sweating depends on how much heat you need to get rid of, and can surpass 5 pints an hour at marathon running pace.

Hyperhydrate pre training until your urine is almost clear. Your kidneys are quite talented; they will keep most of your electrolytes in your system. When you start training, consume some sodium and potassium in your liquid to help maintain your blood volume.

If you lose more than two percent of your body water, your blood gets thicker and your heart will have to work harder on each stroke. Your blood volume will be lower, so less blood will be pumped out of the heart with each beat. Fewer nutrients will get to your muscles, and you’ll be forced to slow down.

According to a study in Medicine and Science in Sports & Exercise, dehydration also lowers your lactate threshold, which makes you feel exhausted earlier in a run.

For a great article and more information on hydration, click here.