Conflicting opinions from the fitness and medical communities concerning eating before exercise can make working out confusing. While one expert advises you to eat a healthy snack before exercising, another may note that you'll burn more fat on an empty stomach. By understanding the potential problems of exercising on a full stomach, you can better understand the conditions in which empty stomach exercise is better. Your own physique and health may dictate whether or not it's bad to work out on a full stomach.
Eating a large meal before exercise can often cause problems, particularly if you tend to engage in strenuous exercise. Doing so can create cramps in your midsection, which is a condition sometimes referred to as the "stitches." You may also feel nauseous. This can prohibit exercise or cut your workout short. Foods that are high in fat or fiber are the most likely to cause discomfort during an exercise session, since they take longer to digest than carbohydrates and other types of food.
In some cases, eating before a meal can cause serious problems if you suffer from exercise-induced anaphylaxis. Anaphylaxis can be described as an allergic reaction to exercise, specifically when you've eaten an aggravating type of food beforehand. You may experience hives, coughing, wheezing, swelling of the face, hands and airways and itchiness. This is triggered by eating foods that you have an allergic sensitivity to before exercise. If you cannot pinpoint the food that is causing the reaction, your doctor may caution against eating anything six to eight hours before a workout.
Fasting Before Exercise
The Australian Institute of Sport points out that exercising on an empty stomach can help you burn more fat, since your body burns fat storage for energy rather than using food energy to sustain your exercise. Still, going without food for too long before a workout could leave you feeling malnourished and susceptible to dizziness, lightheadedness and even fainting. Without sufficient energy to sustain exercise, you might be forced to cut your workout short.
The happy medium between exercising on a full stomach and fasting before a workout is having a small but nutritious pre-workout snack that contains both protein and carbohydrates. For instance, cheese and whole wheat crackers, vegetables and hummus, or a protein smoothie can help give you the energy to sustain a healthy workout without making you feel sick. If you suffer from exercise-induced anaphylaxis, focus on foods that won't cause a reaction and talk to your doctor about treatment and prevention methods.
- Medscape Reference; Exercise-Induced Anaphylaxis; Peter N Huynh, et al.
- Australian Institute of Sport: Eating Before Exercise
- Military.com; How to Avoid Stomach Cramps When Running; Stew Smith
- Beth Israel Deaconess Medical Center; True or False: Wait a Half-hour After Lunch Before Going Back in the Water—Or You Just Might Drown; Diana Kohnle