One of the biggest challenges to conquering the marathon distance is managing fuel needs for the duration of the effort. Because the marathon necessitates running for a period of time that surpasses the body’s ability store fuel, the victory is in pre-fueling and keeping enough in the tank during the run. We’ll discuss fueling leading up to race day here as it tends to be most runners concerns and has the greatest effect on race performance. It doesn’t matter if you fuel appropriately during the 3 to 5 hours you may be on the course, if you start under-fueled, you’ll hit a completely fatigued state far too soon for an optimal finish time.


The common suggestion to eat properly before a race is to “carbo load”, which isn’t entirely untrue, but the biggest consideration is WHEN to carbo load. Most have taken this advice to mean gorging on pasta and breads the evening before their marathon, which is a very poor fueling strategy for the following reasons.

1. Eating large portions of food the night before a race will likely lead to gastrointestinal distress in the morning. If the body can’t process the extra portions of food during the night, this means it also can’t expel those extra portions, leading to unscheduled bathroom breaks during the race or an overall uncomfortable feeling during the run. No one wants to worry about having to go to the bathroom during a race, which can be a common occurrence with all the jostling and liquid consumption that can take place during a marathon.

2. The body takes time to absorb and convert carbohydrates into useable energy (glycogen), so trying to cram all this energy into one meal the night before a race means some of those convertible carbs will go unprocessed, unabsorbed, and leave you with an unfull tank of glycogen.


Sports science has validated “carb loading” as the best way to fuel your body with the types of fuel it will need to get as far and as fast as possible during a marathon race, but again, we must point out how best to fuel in order to run your best. The following suggestions have shown to lead to a completely fueled runner and are practiced by elites at all levels.

1. Load days prior. The body takes in nutrients, but they aren’t all converted or absorbed, necessitating repeated consumption for stable nutrition usage. This means you can eat large portions of food, but some will be excess and go unused. With that in mind, it is advisable to start eating simple carbohydrates 2 to 3 days before your marathon. This doesn’t mean pasta for breakfast, lunch and dinner for three days, but adding a carb-heavy meal at least once a day starting Wednesday or Thursday (for a Saturday marathon) will prepare you best for race day.

2. Concentrate on breakfast the morning before. Due to absorption rates, the new science shows that a carb-heavy breakfast the morning before your race will be your primary fueling meal. Eating something carb dense (pancakes, french toast, etc.), even with a little larger portion size than usual, will keep you fueled for racing the next morning and will, most importantly, be absorbed and expelled before the gun goes off.

3. Stick to normal portions. Wherein some take carb loading as permission to eat with abandon, it’s best to keep to normal portion sizes, allowing your body to process food as it always does, and not lead to unexpected bathroom issues. Especially the night before your race, eat carbs in a normal portion size for the previously stated reason.


Marathoners have the luxury of “indulging” (if you even want to call it that) from time to time due to all the miles run and energy expended during training. But where the advice for healthy eating often revolves around fruits and vegetables, whole foods, and complex carbohydrates, leading up to a marathon there are some advisable changes to make.

1. Cut back on fiber. Especially in the couple days before your marathon, limit your intake of roughage (leafy greens, beans, etc.) in order to avoid slow digestion and GI distress.

2. Simple Carbs. When you start taking in more pasta and bread, skip the Whole Grain options and stick with just plain processed carbs. The reason to eat processed pasta at this point is for the easiest digestion and quickest absorption of carbs. This is why most runners will eat the simple carbs of energy gels during a run and not the slow absorbing, fiber-laden carbs of other more whole foods. Admittedly, you won’t necessarily ruin your run by eating whole grain pasta and bread, but there is certainly no reason to avoid processed options at this point.


Whatever you decide to eat for the three days leading to your marathon, focus on easily digesting, carb-dense foods. The following are easy go-to’s and I rely on them without fail before each goal race I attempt.

White Rice
Quick Oats
Sports Drinks
Energy Bars


Finally, we must consider how to eat the morning of the race. Despite all your great fueling efforts the past few days, your body will have spent some of this energy during the hours of non-eating during the night. With that in mind, it’s best to eat 2 to 3 hours before your race and to, again, concentrate on quick acting carbs. Breakfast options should be limited to 150 to 200 grams of carbs and consist of something like toast with jelly, a muffin and banana, bagel with spread, or even cooked rice cereal. If you are worried about being hungry at the beginning of the race, add a bit of protein (peanut butter is what I always used) to your bagel or toast to help keep hunger at bay. You want to eat these foods 2 to 3 hours (less portions the closer you get to the start) before the race so they are digested when you need to begin.

And don’t forget the coffee (tea, etc.). The endurance benefits of caffeine have been proven time and time again, the optimal time to consume being one hour to 45 minutes before the start of the race.


To recap.

1. Eat simple carbs.
2. Start concentrating on them 2 to 3 days before your marathon.
3. Your most important meal is breakfast the day before your race.
4. Eat typical portions to avoid GI distress.
5. Eat a small breakfast to top off glycogen stores the morning of your race.
6. Don’t forget the coffee.
7. Set a PR!

Scott Spitz

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