I'd like to chime in here and say that I drink a cup or two of black coffee about a half-hour before a run. It warms me up for cold weather running (winter in Seattle) and the caffeine gives me a little boost I need for my daily 5k runs. Now, I'm not sure if this is a completely healthy thing or not, but it works for me. Also, I never add anything to my coffee and I've come to enjoy the taste.