This squeezable powder packs in essential vitamins and minerals that you sweat out during exercise. Just pump a blast (or two for extra flavor) into a water bottle, shake well, and start sipping. Like Nuun, Vitamin Squeeze doesn't deliver calories, but it does have ample electrolytes to quench thirst and B, C, and even D vitamins to supply all-natural energy. We felt totally revitalized after guzzling this drink; so, besides being a solid exercise aid, it's a great midafternoon pick-me-up as well. Just stay away from the caffeinated versions – they give a little too much zip unless you're in the midst of a race – and opt instead for one of four caffeine-free flavors such as Açai Pomegranate Grape. One small, nearly weightless container offers 12 servings, so you can tote it anywhere without worrying about running dry. [$5 per bottle;]