1. Gleukos Sports Fuel
What's in it: 17 grams carbs (glucose), 40 milligrams sodium
Benefit: Your body absorbs glucose faster than other sugars, resulting in quick energy.
Verdict: Lots of carbs, with a clean taste. The sweatiest events may require supplemental sodium. 7.8 liters' worth, $14

2. Gatorade Endurance Formula
What's in it: 14 g sugar (sucrose, glucose), 200 mg sodium
Benefit: Plenty of carbs and lots of sodium are key during long, sweat-soaked events.
Verdict: Like many carb-packed drinks, it may prove intolerably sweet after several hours. A good value at $25 for 24 liters' worth

3. PowerBar Endurance
What's in it: 17 g carbs (maltodextrin, fructose, glucose), 190 mg sodium
Benefit: High sodium for long, sweaty races and a carbohydrate blend that seems to provide extra fuel as exercise stretches past three hours.
Verdict: Sweet and syrupy but a good taste with low froth. 12 liters' worth, $20

4. Gu Sports GU₂MO
What's in it: 13 g carbs (maltodextrin, fructose), 120 mg sodium
Benefit: Plenty of complex carbs and a moderate sodium level cater to medium-length events in temperate conditions.
Verdict: Sufficient carbs without tasting too sweet. 16.5 liters' worth, $18

5. Accelerade Advanced Sports Drink
What's in it: 14 g carbs (sucrose, fructose), 127 mg sodium, 3 g protein
Benefit: There are enough carbs and sodium to support long workouts, and the added protein may help reduce muscle damage.
Verdict: Choose it for high-intensity training when fast muscle recovery is crucial. 10.7 liters' worth, $26

6. Clif Shot Electrolyte Replacement Drink
What's in it: 19 g carbs (sucrose, maltodextrin, maltose, glucose), 200 mg sodium
Benefit: A high-performance drink that's almost entirely organic, with lots of salt for sweatfests.
Verdict: The drink with the most sugar here is also among the cleanest tasting, though it's on the pricey side. 10.8 liters' worth, $22