The go-to drink mix for distance cyclists, Nuun U Natural Hydration offers a different, but totally effective, way to rehydrate. Drop a 7-calorie quick-dissolve tablet into your water bottle for a light, tangy – not grainy, chalky, or medicinal – drink that's packed with the electrolytes sodium, potassium, and magnesium; vitamins A, B, and C; and a whole bunch of minerals. Beyond quenching thirst, the caffeine-free Nuun made us feel energized, alert, and ready to tackle more miles in the bike saddle. But since it has scant calories, you may want to pair Nuun with a nutrition bar or Clif Shot Bloks for added fuel. Our favorite flavor: Tangerine Ginger. [$7.95 for 16 tablets;]