Now that you've been diligently running your 15 to 20 miles every week, you're up for something a little more challenging. The half-marathon is the fastest growing road race in the United States, according to Running USA, especially for women. And at 13.1 miles, it's certainly a lot less daunting than the full marathon. But just because it's a shorter race doesn't mean you don't have to train for it. This includes modifying your diet so you have the energy to complete the run.
Carbohydrates
If you want to have the energy to get through a half marathon, you have to eat carbs. While running, your body uses glycogen, which is the storage form of carbohydrates, to fuel your muscles. Glycogen storage improves throughout the training process. The carbs in your diet help build your glycogen storage capacity. Ideally, 60 to 70 percent of your calories should come from carbs. Healthy carb choices include whole grains, fruits, vegetables and low-fat dairy products.
Protein
Part of the training process for a half marathon is building up your muscle strength and endurance, and this is where protein comes in. Your body needs protein to help rebuild and repair muscle after your long runs. You actually need 50 percent more protein now than you did when you weren't exercising at all. Twelve to 15 percent of your daily calorie intake should come from protein when training for a half marathon. Good protein choices for your diet plan include poultry, seafood, lean red meat such as pork loin or sirloin, beans, soy foods and low-fat dairy products.
Fat
While training for a half marathon certainly helps you burn a lot of calories, it doesn't give you free reign to eat whatever you want, and that includes foods high in fat. Like everybody else, you should limit your daily fat intake to 30 percent of your calories. In addition, fat choices should come from the healthier variety, such as nuts, seeds, oils and fatty fish such as salmon and tuna.
Meals While Training
While training for your marathon, it's important that you eat healthy, balanced meals throughout the day. About two to four hours before you run, you should eat a 400-calorie meal that is low in fat and includes both carbs and protein, such as some grilled chicken with a sweet potato and steamed broccoli. Within 30 minutes of completing your run, you need to eat another carb and protein meal to help with recovery, such as a tuna sandwich.
Race-Day Eating
What you eat the day of the race also matters. Two hours before you start, eat a high-carb, low-fiber meal with some protein, such as a banana and a slice of toast with nut butter, and drink 20 ounces of water. During the race you need to continue to drink 5 to 12 ounces of water or a sports drink every 15 to 20 minutes. You also need to continue to eat simple carbs -- jelly beans, bananas or pretzels -- every 45 minutes during the race to keep up energy levels.
