No marathon training plan is complete without attention to diet. Consuming the right nutrients will help you complete your training miles, recover properly and have plenty of fuel for race day. Without proper nutrition, you risk hitting the wall at some point after the 20-mile mark during your marathon run of 26.2 miles. You must consider nutrition for all phases of your race - from training until after the race - for optimal results.
Your diet should consist of 65 to 75 percent carbohydrates during training, says runner and coach Rick Morris in an article for Running Planet. Carbohydrates provide the best source of energy for your muscles. At most meals, choose healthy versions of carbohydrates - such as whole grains, whole wheat bread, potatoes, yams and fresh fruits or 100 percent fruit juice - as these provide nutrients and fiber along with the carbs. In addition, the healthy carbohydrates burn more slowly than white bread, candy and soda - giving you long-lasting energy. Consume about 25 percent of your calories from lean proteins. Skinless chicken breast, flank steak, tofu, beans, low-fat dairy and eggs are optimal sources. The remaining 10 to 15 percent of your calories come from fats. Opt for heart-healthy unsaturated fats such as olive oil, avocados, nuts and seeds. On days you do hard training runs, have 20 to 25 grams of your protein 30 minutes post workout to help your muscles recover and build stronger, recommends the International Association of Athletics Federation, along with 0.7 grams of carbohydrates per pound of your body weight to refill the energy stores in your muscles. You should consume quick-digesting carbohydrates in the form of a gel or sports drink during a training run lasting longer than an hour.
Monitor your calorie intake during training - eating too few calories will leave you feeling fatigued and without energy to complete your workouts. Women who consume too little risk developing irregular periods and possibly low iron levels. Remember that all the running you are doing does not give you a license to gorge. Eating more calories than you burn daily will lead to weight gain, which will slow you down come race day.
Week Before the Race
Carbohydrate loading to completely fill your glycogen - or energy - stores in the week before race day may help improve performance. MayoClinic.com suggests reducing your carb intake to about 50 to 55 percent of your daily calories seven days before the marathon while you continue to train as normal. About three days before the race, taper significantly and boost your carb intake to about 70 percent of daily calories - or the amount equal to 3.5 to 4.5 grams per pound of body weight. Because carbohydrates hold water, you may gain a few pounds during this process. Carb-loading can increase the levels of stored glycogen in your muscles from 25 to 100 percent, MayoClinic.com notes - but this isn't true for everyone. Men tend to have better results with carb-loading than women. If you have a medical condition, such as diabetes, that restricts your carb intake - consult your physician before trying this practice.
Fueling up on race day is essential to proper performance and dealing with hitting the wall during a marathon. Your muscles can only store, at most, 1,800 calories worth of fuel - which only puts you to Mile 20 or 22 in a marathon, notes Morris. Endurance coach Chris Carmichael recommends your pre-competition meal contains about 80 percent carbohydrates and 10 percent protein. Consume your meal at least two to three hours before the race so you have time to digest. Good options include a cinnamon raisin with a banana or a breakfast burrito with egg and potatoes. During the race, consume between 30 and 60 grams of carbohydrates per hour of work, Carmichael advises. An energy bar typically contains 45 grams of carbs, a gel contains 25 grams and a sports drink contains 36 grams.
After the Race
Just as you did during training, eat a meal that contains carbohydrates and a bit of protein immediately following the race to help the recovery process. Hydrate and snack throughout the next 24 hours. Podiatric surgeon Steven Palladino, writing for "Marathon & Beyond," recommends you increase your intake of protein slightly in the days after the race until you no longer experience muscle soreness. The increased protein might help with muscle repair and expedite recovery.
You must stay adequately hydrated throughout training and race day. For training and competition, the American Council on Exercise recommends you drink 17 to 20 ounces of water two hours before the start of a workout and 7 to 10 ounces about every 15 minutes during exercise. For every pound you lose during your exercise session, drink 16 to 24 ounces post run. Workouts lasting longer than 90 minutes or runs performed in hot conditions require some electrolyte replacement to keep your muscles firing properly and preventing too much sodium loss. Sports beverages, gels and salt tablets are helpful in maintaining proper electrolyte balance.