Sugar actually helps the stomach empty faster, which is important for maintaining hydration on those hot days when you're sweating 2-3 liters an hour. If you don't want the HFCS (and I'm with you on that one - not to mention the artificial colors and flavors, yecch) and don't want to have to clean fruit juice out of your bottles, you can mix your own hydration solution.

1 Cup Sugar
4 Tsp Salt
2 Tsp Potassium Chloride (Salt Substitute)
2 Tsp Sodium Bicarbonate (Baking Soda)

Shake or stir it vigorously to mix and keep it in an airtight jar, preferably glass. Use 3 Tbsp per liter of water. You can add essential oils for flavoring if you want.