You’ll Run How You Eat: Nutrition & Marathon Training

By Kerry Clifford

Kerry is a Senior Dietetic Intern and Masters Candidate at Rush University Medical Center. This post kicks off the new Student Series here on the CAND blog, which features Chicago-area dietetic interns every Thursday. Kerry is currently training for the Chicago Marathon – keep reading to get Kerry’s research and first-hand insight about nutrition and marathon training. For Kerry’s full bio, please see below.

You’ll Run How You Eat: Nutrition & Marathon Training

Performance ability during a race and training is totally dependent upon nutrition status. Many people have heard about carb loading, but what does that really mean? While making sure that the runner is getting enough carbohydrate (60-65% of total calories), it’s important to remember that getting adequate protein (15-20% of total calories) and fat (20-25% of total calories) is also a crucial part in a marathon training nutrition plan.

It is recommended that the runner eat about 3 times the amount of carbohydrate as protein (a 3:1 gram ratio). But why are carbs so important? Because the human body stores carbohydrate as glycogen (energy for exercise) in the liver and muscles. For marathon runners, the body also stores and relies on fat to fuel exercise as it is a high-energy molecule. Without these two key nutrients, the body would never be able to sustain a long-distance run.

Dietary carbohydrate is directly related to carbohydrate stored as glycogen. So that means consuming enough carbohydrate as early as three days prior to a long run is crucial for performance. It is suggested that a runner consumes about 7 to 8 grams of carbohydrate for every kilogram of body weight (or 2.2 pounds). For example, a 70-kilogram (154-pound) person should consume 450-700 grams of carbohydrate on each of the three days prior to the distance run. It is important that the runner consumes what is best tolerated and also to include fat and protein sources in his or her everyday diet to maintain health.

In addition, athletes are advised to eat 2 to 3 hours before exercise to decrease the risk of “bonking” or “hitting the wall” during exercise (this usually happens around mile 18 of the marathon). In any exercise lasting for longer than 60 minutes, carbohydrate intake between 30 to 60 grams per hour will extend exercise ability (things such as Gatorade, a banana, or energy chews are good options). Immediately after exercise, the recovery meal or snack should contain high amounts of carbohydrate and protein and a low amount of fat to speed up nutrient absorption for muscle repair.  Hydration is also important – in the heat, some runners may need around 6 to 7 liters of water per day to keep adequately hydrated.

Photo by Kerry Clifford

It’s important to eat properly as soon as you begin training for a marathon because, often times, the nutrient needs of the runner are higher during training than the actual race because our bodies are building and repairing muscle. And keep in mind – Rest Day nutrition is equally as important as Race Day nutrition! Whether you’re training for the Chicago Marathon in October or just enjoying daily exercise, optimal nutrition can help you perform at your best!

Nutrition Tips for the Runner

• Test out your nutrition plan during training and avoid eating anything new close to the race so that you won’t have any uncomfortable gastrointestinal symptoms on Race Day
• Avoid adding sugar and fat during carbohydrate-loading – instead, increase nutrient dense foods
• Try other types of carbohydrates beyond pasta to carb-load: quinoa, spelt, potatoes, and brown rice are great options and are packed full of nutrients for runners
• Use smart phone applications like MyFitnessPal to keep track of what you eat to see how you’re doing during your training periods

Kerry Clifford is in her second year of Rush University Medical Center’s combined Dietetic Internship and Masters of Science program in Chicago. Kerry received a BS in Dietetics and a BS in Fitness and Health from Purdue University in 2012 and is very passionate about combining a physically active lifestyle along with nutrition. Kerry’s special interests include gastrointestinal health and weight loss nutrition. When Kerry graduates from Rush in June of 2014, she hopes to pursue a career in clinical nutrition and eventually own her own business to motivate people towards a healthy lifestyle. You can contact her at Ke**************@**sh.edu.