Pre-Workout meal – when and how much? Depending on how much time you have, it’s ideal to have a pre-workout meal about 2 hours before exercise that contains ~300 to 500 calories, OR have a smaller meal/snack with less calories, 30 to 60 minutes before you train. Pre-workout meals will vary from person to person because some people take a longer time to digest certain foods. It’s best to listen to your body and notice how you feel after you eat.