I drink plenty of fluids during rides, including Cytomax. For centuries/metrics, I'll take one Potassium Magnesium Asparate capsule (available from GNC) each day about 3 days before the ride and one the day of. Breakfast includes Raisin Bran - high pottasium and magnesium content with a carb bonus. Long ride nutrition - bananas/Clif Bars. The most critical item is hydration. The hotter it is the more you have to drink. And you must force yourself to drink.