When it comes to exercising, there are two kinds of people in the world: those who work out in the morning and those who'd rather not get up before the sun. No matter which category you fall into, what you do in the morning can help or hurt your metabolism; just ask trainer Yumi Lee, co-owner of Reebok CrossFit Lab who's known for getting Jessica Alba into shape. While you can count Yumi in the morning exercisers club, she has a recommendation for those who don't: eat breakfast almost as soon as you wake up. "Either start off with a good breakfast or a good workout," she says. "If you're going to work out within an hour of waking up, then don't eat. But if you can't work out within an hour of waking up, then eat. Either your workout or eating a healthy breakfast is going to jumpstart your metabolism."
If you are a morning exerciser, Yumi recommends not eating anything before a workout, especially if you normally experience stomach discomfort while you exercise. If you do need fuel before a workout, she suggests a small protein shake, a piece of toast with a protein, or a small bowl of oats, but "not too much; if you can burn off what's in stores from the day before, then you're better off than just burning off what you ate for breakfast," she says.