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Marathon Race Day Nutrition

When I did my first marathon, I carried a liter of sports drink in a hydration reservoir in a waist pack. It seems ridiculous when I think about that now. I've learned a lot about race nutrition since then. My current nutrition plan is both simple and minimal, yet provides me enough energy to perform at my best. There's a myriad of information out there about what to eat and drink during a marathon. Newbies often feel overwhelmed by all of the information out there. I know I was.

Building a nutrition plan should ideally be done months in advance of a race. It should be practiced on long runs to make sure your stomach agrees with it. I'll start out by saying that there isn't one right answer that works of everyone. It's ultimately up to you to decide what energy sources work best for you, but hopefully this guide will help alleviate some confusion. There are a couple of principles to understand first:

  • In most cases, carbs are counterproductive to developing marathon endurance. The more fat-adapted you are, the longer you can go without taking in extra calories. However, on race day, carbs are your best friend. Your body can store a certain amount of glycogen (sugars) that will be your first source of energy before fat stores are used. Those glycogen stores should be at maximum capacity when you toe the start line.

  • You will burn WAY more calories than you could ever replace during a race. That's okay! Most of your calories will come from body fat. I personally burn approximately 1500 calories per hour during a race (which is a lot, I know), yet I replace only about 10 percent of that.


Most marathons start at 7am. Plan on waking up at least 3 hours before the race - yes, that's 4am. Basically you should allow enough time for those breakfast calories to get fully absorbed before the race starts. You want your breakfast to consist of mostly carbs. Protein and fat won't be absorbed quickly enough to be of much use. The goal here is to get your glycogen stores topped off, which is really all you need your breakfast to do. And you actually don't need that much food to do that. This varies person-to-person, but I typically eat a homemade oatmeal with chia seeds and brown sugar, probably about a 1/2 cup worth. I've also had a sweet potato with brown sugar or coconut cream. A bagel with honey would be another good option.

It's up to you to find a breakfast that works for you. I would recommend against foods with a lot of fiber (like fruit), to help you avoid those unpleasant mid-race bathroom breaks. If you're a coffee drinker, you will probably want to have your coffee on race morning. After all, caffeine is a performance enhancing drug! Some athletes even perform better without any breakfast, but you'll need to be relatively fat-adapted to get away with that.

1 hour before:

By this point you'll likely be hanging out at the start line just waiting. Have some sports drink or water to sip on. You want to be well hydrated for the start, but avoid drinking excessive amounts of water - 16-24oz. should be plenty before the race. 15 minutes to go and you should take a gel, sports drink, etc. This will ensure that your glycogen is fully topped off and give you a boost of energy right at the start of the race.


You should aim for 30-60 grams of carbohydrates per hour. If you're going to be finishing around 4-5 hours, stay on the lower end of that range. Your exercise intensity will be lower and thus more of your energy will come from body fat than glycogen. For the athlete finishing closer to 3 hours, you should stay closer to 60 grams. Your intensity will be higher and thus you'll use more glycogen. Avoid going over 60 grams though as too many calories will cause indigestion and can potentially cost you the race. Too little and you'll bonk in the later stages of the race and may end up walking the last few miles.

I personally carry a 4oz. flask of EFS Liquid Shot and supplement with on course fluids. This gives me enough energy and minimizes the amount of stuff I have to carry. I just hold the flask in my left hand for most of the race and stuff it in my jersey pocket once it's empty. I used to think it would be really annoying holding something like that for that long, but it's not really. You just kind of forget it's even there. I generally take a few sips every 30 minutes, but have the flexibility to adjust as needed. Gels should always be followed up with water (approx. 3-4oz.) to ensure proper digestion.

Speaking of water, most marathon courses have aid station every 2-3 miles and are almost always well-stocked with water. Unless you're doing a trail run, chances are you won't need to carry any water. The amount of water you'll need to drink will vary widely depending on the temperature, humidity, sweat rate, etc. A rough approximation would be about 24 oz. of water per hour during the race. Ideally a 'sweat test' should be performed to determine how much water you lose due to sweat while running. A good rule of thumb is to take a cup of water at each aid station. If you're using sports drinks and not gels, you probably won't need any extra water unless you start to feel thirsty.

If you do encounter stomach issues near the end of the race and can't get any calories down, your body has a very useful adaptation to help you get through this. Our taste buds are highly sensitive to foods containing high levels of energy (sweet foods). The second our taste buds sense something sweet, it sends a message to the brain telling it: "energy is on the way!" This triggers the brain to release some of the energy it's keeping in reserve. So if you need a boost of energy but can't get anything down, simply swish some sports drink around in your mouth, then spit it out, and the energy will come! Don't do this throughout the race or else you'll bonk hard. This should be a just-in-case tool to help you get through the last few miles.

Prone to getting muscle cramps? There's a solution for that too! Mustard! Simply eat a packet of mustard when the cramp starts and within 2 minutes the cramp will be gone. It's believed that the vinegar in the mustard triggers some reaction in the brain to stop the cramping. Pickle juice works too, but mustard packets are much easier to carry during a race. Cramps are caused by a number of things, one of which being low sodium levels in the blood. The mustard will also help replenish some of those salts, take extra salt as needed.

An especially hot race may dictate the use of additional salt. Salt tablets are a simple way to carry extra salt during a race. Look for those made specifically for endurance races, such as those made by SaltStick. If I suspect I might need some, I bring enough to take one every hour. If I'm doing an especially hot race, where I know I'll need them, I bring enough for two per hour. Simple things like potato chips or pretzels work too, but are more difficult to carry.

Recommended Gels:

Recommended Sports Drinks:

Recommended Nutrition for those with Diabetes:


At this point your main focus should be celebrating your accomplishment! Replenish your fluids and salts, and eat whatever sounds good! Pizza is always my favorite post-race treat.

As always, be sure to practice every aspect of your nutrition plan well in advance of the race. Refine as needed. Race day is not the time to be trying anything new and any nutrition mistakes will be costly. But a well thought-out and well-practiced nutrition plan may be all that's standing between you and that ever-coveted PR!


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Hi, I'm Kevin.  I'm a triathlete and mountaineer, among other things.   This is where I get to share my adventures with you.  


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14,410ft - Summit of Mt
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