Juicing can be a good way to get in some extra fruits and vegetables: Supplement, don't cleanse. Nutritionists largely agree that juicing can offer a low-fat, nutrient-rich jolt of energy when added to already healthy, balanced diets—but as far as the cleanse-for-weight-loss meal replacement trend? Skip it. Juice digests quickly, and can cause the type of extreme hunger that leads to overeating and binging. "Drinking juice in lieu of eating food is not healthy or sustainable, no matter how nutrient-packed," says Marjorie Nolan Cohn, RD, a national spokesperson for the Academy of Nutrition and Dietetics. Juice cleanses (read: fasts) can also lead to unstable blood sugar, headaches, and lightheadedness. So, yeah, your workouts aren't going to happen; or you'll be so exhausted during them you won't have the energy to keep up and can up your odds for injury.
Pick the right ingredients. Certain vitamins are more easily absorbed as juice, like vitamin C and Bs, while others, like vitamin A, E, K are best taken through the full digestion process, says Cohn. And some vegetables, such as tomatoes, actually provide more nutritional value when cooked, points out Kelly O'Connor, RD, LDN, a registered dietician at Baltimore-based Mercy Medical Center. Keeping all this in mind, these best bets that will maximize nutrition: leafy greens (spinach, collard greens, swiss chard, kale, mustard greens), kiwi, papaya, grapefruit, red bell peppers, broccoli, strawberries, oranges, asparagus and garlic. Cherie Calbom, MS, CN, author of The Juice Lady's Big Book of Juices & Green Smoothies also favors parsley, blood-pressure-lowering beets (combine with carrot or apple to enhance taste), inflammation-fighter ginger root, potassium-packed cucumbers, and antibacterial lemons. Avoid overly mushy or tender fruits, like bananas (if craving potassium, use half) and peaches, which can make your juice too thick and mushy, says Cohn.
Find the perfect mix. Warning: Vegetable juice might not knock your socks off at first, so you've got to experiment. Plot how you'll keep a variety of produce stocked, then have fun with it. Start with two cups of greens, which can taste bitter, balanced by one piece of fruit. Then, play around with the ratio, adding cayenne pepper or cinnamon for extra seasoning if desired. (Still not sure where to begin? We asked the experts for their favorite combos—grapefruit-orange-kale-cucumber for Cohn and carrot-apple-ginger for Calbom.)
Sip fast. Whipping up batches of liquid vitality for the week, or even day, isn't most potent. "Guzzle that juice immediately," says Cohn. "By changing the texture and integrity of fruits and vegetables from solid to liquid and removing protective skins, the foods quickly start to lose nutrients."