Carbohydrates are a runner’s main source of fuel, but they are only stored in limited amounts in the body as blood glucose, liver glycogen and muscle glycogen. Regular intake of healthy carbohydrates will keep you nutritionally energized to meet your daily training needs.
Understanding how many carbohydrates you need is important so that you know how to keep your fuel tanks loaded. Melinda Manore, a registered dietitian and professor in the Department of Nutrition and Exercise Sciences at Oregon State University, recommends that athletes consume 5 to 10 grams of carbohydrates per kilogram of body weight on a daily basis. She suggests that you stick to the lower range on lighter training days and increase to the higher range as race day approaches. So for a 150-pound runner, this would amount to 340 to 680 grams of carbohydrates per day. Select nutrient-rich carbohydrates such as whole grain products, legumes, fruits, vegetables and low-fat dairy products that also provide generous amounts of vitamins, minerals, phytonutrients and fiber.
Fueling up before a training run or competition is vital and guarantees a full fuel tank for optimal performance. A 2002 study in the "International Journal of Sports Nutrition and Exercise Metabolism" showed that consuming 2.5 grams of carbohydrates per kilogram of body weight 3 hours before exercise improved running capacity by 9 percent. These carbohydrate-rich pre-exercise meals provide 86 to 101 grams of carbohydrates: 1.5 cups of cereal, 1 cup of skim milk and 1 cup of orange juice; or a turkey sandwich with 2 slices of bread and 2 ounces of turkey, 1 apple and 6 ounces of yogurt.
Carbohydrates During Exercise
Your main goal during any long workout is to maintain your blood glucose levels and thus, energy levels. If your workout is longer than 60 minutes, Andrea Hacker Thompson of the American College of Sports Medicine recommends an intake of 30 to 60 grams of carbohydrates per hour. This can be in the form of sports drinks, energy gels, energy bars, energy beans, honey, oranges or bananas.
Post-exercise carbohydrates are critical in ensuring muscle glycogen replenishment and preparing you for your next workout. If you do not replace your carbohydrates, subsequent training sessions or competitions will suffer. Heather Hedrick Fink, Alan Mikesky and Lisa Burgoon, wrote the study "Practical Applications in Sports Nutrition," and noted that endurance athletes should consume 1.2 grams of carbohydrates per kilogram of body weight within 15 to 30 minutes after exercise and then repeat that dose every hour for 3 to 4 hours. They suggest whole food carbohydrates, such as fruit, chocolate milk, whole-grain bagels or fruit yogurt. Sports drinks can also be used immediately after exercise. (see ref 4 page 369-370) As recovery continues, add more whole-food carbohydrates, such as pasta, rice, legumes, fruits and vegetables to your meals.