You know when your body's running at its best. You feel energized, powerful, and utterly invincible in the gym. Much of that can be attributed to your nutrition—specifically, the foods you eat before your workout.

If you don't want to slog through your workout suffering from bouts of nausea, fits of stomach cramps, or waves of acid reflux, heed the advice of Jim White, R.D., A.C.S.M. H.F.S., Academy of Nutrition and Dietetics spokesman, owner and president of Jim White Fitness & Nutrition Studios. White has highlighted the foods that have no place in your pre-workout plan, so there won't be anything holding you back in the gym, in the pool, or on the track.