Beetroot — a member of the amaranth family — isn’t the same as the canned and jellied beet that will make its appearance on numerous Thanksgiving tables this month. The juice of this green leafy vegetable may boost stamina and allow you to exercise 16 percent longer, according to a report published in the Journal of Applied Physiology. (The tested dose was 500 milliliters daily.) How can a vegetable extract give you more energy? The U.K. researchers believe that beetroot juice’s nitrate content may reduce the uptake of oxygen to an extent that can’t be achieved by any other means, which makes exercise less tiring. We’ll drink to that.