Cardio exercises require a lot of energy to be performed. So before a cardio workout, you need to eat food that will give you lots of energy while at the same time not fattening. Best food items to have before a cardio workout include fruits, vegetables, whole grain cereals, oatmeal, and low-fat milk. You can have food that is rich in protein as well, but ensure that you consume products like meat, two to three hours before your workout. Things to avoid before a cardio workout include junk food, sodas, candy, and high- calorie food. These are not only unhealthy but also take a long time to digest. If a proper gap before a workout is not maintained, it can make you feel sick during the workout.