You can still pack a smoothie with veggies if the green from a kale or spinach smoothie scares you off. Beets are full of B-vitamins, potassium and folate, and turns your drink a pretty shade of purple. Plus, the nitrates in beets turn to nitric oxide in the body, improving blood flow and boosting endurance during a workout, says Passerrello. Here are even more reasons to eat more beets. Unlike leafy greens, though, don’t toss beets in with a heavy hand. “They’re starchy, so you want to watch how many you put in,” says Passerrello. “If you’re using beet juice, it could be a lot of extra calories.” Whip up Nutritional Foodie’s Beet the Cold Power Smoothie.