What to Eat Before a Workout (and How Long You Should Wait Before Hitting the Gym)

In general, eating some combination of protein and carbohydrates before a workout to sustain energy and build muscle is advised, says Kate Patton, RD, who specializes in sports nutrition at Cleveland Clinic in Ohio. On the other hand, foods with a high amount of fat or fiber (think a grilled cheese sandwich or broccoli, respectively) should be avoided, as they may cause stomach upset and cramping. But what you should eat before a 30-minute power walk is going to look different from what you eat before a 20-mile training run. Here’s what you need to know. If you’re exercising for less than an hour first thing in the morning, McDaniel and Patton agree that you don’t necessarily have to eat anything. “If you have an early workout that’s easy or light and you’re trying to lose weight, it might be best to have a glass of water but skip the food,” says McDaniel, noting that this encourages your body to burn a greater percentage of body fat to fuel your workout. In addition, previous research found that people may burn more fat over the course of 24 hours if they work out before eating breakfast compared with exercising later in the day.