With more calcium than milk and more iron than spinach, watercress is a fantastic ingredient for any healthy green juice. Not only does it pack in maximum flavor, it's also rich in many vitamins—A (in the form of beta-carotene), C, E, and K—and excellent in aiding calcium intake. Claire Rogers, editor of The Goodness of Greens, recommends juicing watercress with sulphur-rich asparagus, tart green apples, pineapple, and cucumber to make a light, fresh, and tangy juice for breakfast. The bromelain contained in pineapple also assists in digestion by helping to break down proteins. Do your body some good before the gym, after a long morning run, or treat yourself for just rolling out of bed.