Because running is a high-impact exercise, the constant jostling of your stomach means eating a big meal right before a run can make you feel slow and potentially lead to nausea and vomiting. However, you need food as an energy source before a run to ensure that your muscles do not run out of glycogen, the stored form of carbohydrates. While the right foods for you can vary, there are some basic rules to follow that can help you prepare for a great run.
As a runner, carbohydrates are your friend. This is because carbohydrates are a fast-acting source of energy for your body. About an hour or less prior to your run, you can eat a high-carbohydrate food that is low in fat. Go Ask Alice, a health resource from Columbia University, recommends foods such as crackers, bagels and breads. However, if you will be running for longer than an hour, you may need a longer-lasting carbohydrate source, such as yogurt, banana or another type of fruit.
Because marathon running involves running over the course of several hours, what you may eat before a run can differ. For example, some runners use sports gels, bars or beans that resemble jelly beans and contain a glucose solution that gives you extra energy. Others may drink half an energy drink and eat half a sandwich before running to start anticipating the loss of electrolytes via sweat. Ensuring that you get enough electrolytes before, during and after a marathon can help prevent dehydration after the race.
Solid Food Considerations
Some runners’ stomachs cannot handle having solid food before a run. In this instance, a glass of juice or 4 ounces -- 1/2 cup -- of a blended fruit smoothie can be enough to give you energy without contributing to nausea. If you have difficulty eating solid foods before running, just remember to supplement your diet with extra carbohydrates post-run to ensure that you replace your energy stores and prevent fatigue.
Foods to Avoid
Eating high-fat foods just before a run can lead to major stomach upset. This is because fats take longer for your body to digest. When you run, the food may feel as if it is sitting in your stomach like a heavy weight. Because physical activity causes your body to shut off blood flow to your stomach in favor of areas such as your moving legs and arms, high-fat food sources can take even longer to digest. For this reason, avoid foods like peanut butter, red meat and cheese prior to your workout.