Marathoners load up on pasta and bread the night before a big race -- sometimes called carbo-loading -- to make sure their bodies have enough energy to burn to keep them going the distance. But cardio on a full stomach can also lead to side effects, like indigestion and cramping. A good rule of thumb is the harder the workout, the more you should have in your stomach, but not so much that your stomach hurts during your workout.
Cardio Benefits
Adding cardiovascular exercise into your workout can yield a host of health benefits, including improved heart health, increased metabolism and increased cardiovascular endurance, according to Bodybuilding.com. “Most individuals performing cardio are using it as a way to burn off excess calories and since you are moving the body, it is going to increase the need for energy,” says Shannon Clark, a personal trainer with a degree in exercise science and sport performance. In other words, she says, eat beforehand.
Permission to Eat
The harder you plan to work, the more you should eat, says MayoClinic.com, which recommends eating large meals no more than three to four hours before a workout, smaller meals no more than one to two hours before a workout and suggests small snacks if you feel hungry before or during a workout. “Snacks eaten soon before exercise probably won't give you added energy,” says MayoClinic.com, “but they can help keep up your blood sugar and prevent distracting hunger pangs.” Bottom line, do what works for you.
Conflicting Opinions
Not everyone agrees that working out on a full stomach is a good thing. If you fast before your workout, according to a 2010 study published in the “Journal of Applied Physiology,” your body will deplete its caloric store and start burning fat for fuel. The more calories and fat you burn, the more weight you can lose. People with chronic health conditions like diabetes should not go into a workout hungry, since your blood sugar will be low, according to findings of this 2010 study. Your doctor can help you decide if working out before or after a meal is right for you.
Low-Carb Fatigue
Of course, not every meal will help your workout in the same way. Bodybuilding.com recommends eating carbs, which will fuel your body and likely keep you from fading before you finish. Depending on the intensity of your workout, you may not want to overdo it, since your body will convert surplus carb calories into fat. But if you’re going all-out, says Bodybuilding.com, and interested in cardiovascular health benefits “you’re far better off choosing to eat beforehand and keep up with higher-intensity sprints.”
