If this is you: Sip a cup of green tea 20 to 30 minutes before you run. The caffeine will pep you up and power you through to the last step, and its antioxidants may help with endurance, too.
If this is you: Try coconut water; its chock-full of cramp-preventing potassium (15 times that of most sports drinks) and has less than 50 calories per cup. Try 8 ounces before or during your run to stay pain-free.
If this is you: With its perfect ratio of carbs to proteinplus the calciumchocolate milk is an excellent way to help your muscles recover postworkout. Drink a cup within 30 minutes of finishing a long run, when muscles are most receptive.
If this is you: A sports drink, with body-replenishing sugars and electrolytes, is the best way to stay hydrated. Choose one thats free of artificial colors, flavors, and preservatives (I like CLIF Quench), and sip 4 to 6 ounces every 15 to 20 minutes during your workout.