Nutrition for Marathon Training

by Eric Bofinger

This may be hitting the blog a little late with the gun for the Philadelphia Marathon scheduled to go off in about 72 hours.  But not enough can be said about proper nutrition for marathon preparation. Our bodies store energy in a few different ways, including stored fat, carbs, and in extreme circumstances our bodies can burn stored protein in the furnace. In terms of marathon running, it is to our advantage if we are using stored carbohydrates (glycogen) to maximize our performance since metabolizing stored carbohydrates requires less oxygen than the other viable fuel sources. Naturally, our body stores 2000 kcal of energy as glycogen, 1500 kcal in skeletal muscles and another 500 kcal in the liver. If we can assume that we burn energy at the rate of 100 kcal/mile then we will run out of energy at mile 20, known as “THE WALL.” This is when the body uses all of it’s carbohydrate energy stores and has to rely on the slower burning fuel sources like fat. By slower burning fuel, I mean it will make you run slower. Therefore, the only way a runner is able to successfully finish a marathon is if they a.) increase their carbohydrates stores, or b.) take in carbohydrates during the race.

Often marathon runners carbo load before a big race and some even do something called the depletion / reloading phase, which is a controversial topic of discussion. Starting a week before the race consume mostly proteins and fats for 4 days. The 4th day should also include your last ‘hard’ workout before the race. This significantly depletes your glycogen stores, leaving your muscles hungry. The following 3 days should be mainly carbs. For the heavy carb days I do something that may seem unconventional for some but intuitively it makes sense to me. I try to eat a low residue diet, little fiber, whole wheat, roughage, etc. My rationale is that I need to consume as many calories as possible without bulk and getting too full. Generally the only adverse affect of carbohydrate loading is weight gain caused from water weight; with stored carbohydrates comes stored water.

The main thing with nutrition for marathon running that I’ve found is timing. If your marathon starts at 7am breakfast needs to be at 4 am. Generally, I try to get on a schedule of a 4am breakfast and a 7am run at least in the week before the marathon. Maybe this means eating and going back to bed.. but I don’t think you can say enough about getting your bio rhythms in sync. The day of the marathon I like to eat an English muffin with honey, banana, one serving of low fiber oatmeal, and Gatorade (high energy to bulk ratio). Typically this is the breakfast I eat the entire week to see how my stomach feels when I run.

Fuel during the race is extremely important in order to bridge the gap between carbo loading and hitting the wall. Don’t feel like you need to be a victim to corporate marketing and consume only energy gels, gus, beans, blocks, & drinks during the race. The most important thing that you need to figure out is what works for you. Remember, it’s ok to eat real food. Just make sure you practice on a training run to see how your stomach will react to the food. Another key point is to front load your eating during the race. Don’t wait until you are at mile 20 out of energy and waiting for the sag wagon to pick you up.

Good Luck!