A well-balanced pre-exercise snack should include a combination of carbohydrates, protein, and healthy fats for optimal energy and performance. Carbohydrates provide a quick source of energy, while protein helps in muscle maintenance and recovery. Including foods like a banana with peanut butter or yogurt with granola can offer essential nutrients and energy needed for a workout. It's important to consume this snack about 30 minutes to an hour before exercising to allow for proper digestion and maximize performance during physical activity.