Most half-marathon training plans will take you from couch to 13.1 miles in detail. They will tell you exactly how many miles to run on what days, when to taper, and how to pace yourself on race morning. What most of them dedicate about one paragraph to is the thing that will actually determine how you feel at mile ten: what you eat.
Nutrition is not the fourth discipline of a half-marathon the way it is for an Ironman, but it matters far more than most recreational runners give it credit for. The difference between a race that feels strong and a race that falls apart in the final two miles is often not fitness. It is fuel. Specifically, it is whether you went in with enough glycogen stored in your muscles, whether you topped it off during the run if your race takes longer than 75 to 90 minutes, and whether you gave your body what it needed to recover properly after.
This guide covers all three phases: the days leading up to race day, the race itself, and the recovery window after you cross the finish line. It is written for real people training for real half marathons, not elite athletes with sports science staff.
The Week Before: Carbohydrate Loading Done Right
Carbohydrate loading gets a reputation as an excuse to eat a massive bowl of pasta the night before a race, which is both partly true and partly a recipe for showing up to the start line feeling heavy and uncomfortable. What it actually means is a gradual, intentional increase in carbohydrate intake over the two to three days before your race, to top off your muscle glycogen stores so you go into mile one as fully fueled as possible.
For a half-marathon, you do not need to do anything extreme. The distance is long enough that glycogen availability matters, but short enough that a modest three-day increase in carbohydrates will do the job. Think of it less as loading and more as just not restricting. If you normally eat a moderate amount of carbohydrates, bump that up a bit each day in the three days before your race. Add an extra serving of rice or pasta at dinner. Have a larger breakfast. Include a starchy snack in the afternoon. You are filling a tank, not forcing anything in.
What to reduce during this window is fat and fiber. Both slow digestion, and you want your gut to be relatively settled on race morning. This is not the week to try a new high-fiber grain or load up on cruciferous vegetables. Keep meals simple and familiar. Your digestive system will thank you on mile six.
Hydration also deserves attention during race week. Arrive at race morning already well-hydrated rather than trying to catch up on the morning itself. Consistent water intake through the week, alongside normal sodium from food, is what people need.
Race Morning: Timing and What to Eat
Race morning nutrition causes more anxiety than almost anything else in half-marathon prep, and most of that anxiety comes from fear of stomach problems during the run. The good news is that with a little planning, your pre-race breakfast is straightforward.
Aim to eat your pre-race meal two to three hours before your start time. This gives your body enough time to digest and convert that food into available energy without leaving you running on empty. If your race starts at 7 a.m., you are waking up at 4 or 4:30 to eat, which is not pleasant but is worth it.
In general, the meal itself should be carbohydrate-forward, moderate in protein, and low in fat and fiber.
A few examples that work well for most runners: oatmeal with a banana and a drizzle of honey, toast with a light spread of peanut butter and a piece of fruit, a bagel with jam, or white rice with a scrambled egg. Nothing exotic, nothing new, nothing you have not eaten before a training run.
This is a foundational rule of race nutrition: never try anything on race day that you have not already tested.
Everybody is different, though, and certain meals don’t work for everyone based on weight and grams/kg, so make sure to consult with a sports dietitian to find what works for you.
If your start time does not allow for a full meal two to three hours out, a smaller snack 60 to 90 minutes before can work. Something like a banana, a piece of toast, or a small serving of easily digestible carbohydrates. Keep the portion modest since you have less time to digest.
We like to start your race fueling with some quick carbohydrates pre-race (15-20 minutes prior), ~15-30g, like a gel or chew, whatever you will be using during the race
Coffee is fine if you are a regular coffee drinker. Caffeine has well-documented performance benefits for endurance exercise, and if your gut tolerates it normally on training runs, there is no reason to skip it on race day. What you want to avoid is experimenting with caffeine for the first time on race morning.
During the Race: When and What to Take In
Whether you need to fuel during a half-marathon depends on how long you are out there. The general guideline is that for efforts lasting longer than 75 to 90 minutes, taking in carbohydrates during the run will help maintain your energy and pace in the back half. For most recreational runners, a half-marathon takes somewhere between 1.5 and 2.5 hours, which means the majority of people benefit from at least some mid-race fuel.
The goal during the race is not to replace everything you are burning. It is to slow the rate at which you deplete your glycogen stores and to keep your blood sugar stable so that the final miles do not fall apart. A rough target for most runners is 30 to 60 grams of carbohydrates per hour during the run, with the lower end of that range being reasonable for a faster runner completing the race in under 1.5 hours and the higher end for someone out there for two-plus hours.
Gels, Chews, and Sports Drinks
The most practical options for mid-race fueling are energy gels, chews or blocks, and sports drinks. Gels are the most common choice because they are compact, easy to carry, and quick to consume. A standard gel contains roughly 20 to 25 grams of carbohydrates. For a two-hour race, taking one gel around mile four or five and another around mile nine or ten gives most runners adequate fuel through the finish.
Whatever you plan to use on race day, you need to have practiced with it in training. Your gut adapts to processing carbohydrates during exercise, and showing up to race day with a gel brand you have never tried is a gamble you do not need to take. Use the same products, in roughly the same amounts, that you used on your longest training runs.
If you prefer not to carry gels, sports drinks at aid stations can serve the same purpose, provided you know what will be offered on the course and have used that product before. Water is not a substitute for a sports drink in terms of carbohydrate or sodium delivery, but you should be drinking fluids alongside any gel you take to aid absorption and prevent stomach issues.
A Note on Stomach Problems
Gastrointestinal issues during a half-marathon are common and almost always preventable. The most frequent causes are taking in too much too fast, using products you are not accustomed to, eating excess or too close to the start, not training your body with increased intake in training, dehydration, eating fueling products with fiber/fat, or running faster than you trained for. Nerves also play a significant role. If GI distress is something you have experienced in past races, it is worth working through your fueling protocol in detail with a sports dietitian rather than continuing to experiment on your own.
After the Race: Recovery Nutrition
The finish line is not the end of your nutritional job. What you eat in the hours after a half-marathon has a significant impact on how quickly you recover, how sore you feel in the days following, and how well you adapt to the training stimulus of the race itself.
The first priority in the immediate recovery window is carbohydrates to begin restoring muscle glycogen. Your stores have been significantly depleted, and the sooner you start replenishing them, the better. The second priority is protein to support muscle repair. A meal or snack that includes both, eaten within 30 to 60 minutes of finishing, gives your body the raw materials it needs to start recovering.
This does not need to be complicated. A recovery smoothie with fruit, milk or yogurt, and a scoop of protein powder works well. So does a turkey sandwich, chocolate milk alongside a banana, or eggs on toast. The exact composition matters less than actually eating something, because many runners finish a race and then stand around for an hour drinking celebratory beer before eating anything substantial, which is one of the main reasons they feel terrible for the next three days.
In the hours and days after the race, prioritize eating consistently and not underfueling. This sounds obvious, but a lot of runners fall into the trap of eating less after a race because they are no longer in heavy training. Your body is still doing significant repair work in the 48 to 72 hours after race day. It needs fuel for that process. Honor the effort you put in.
The Rule That Overrides Everything Else
Every specific piece of advice in this guide comes with one condition: it only works if you have practiced it. The single most important principle of race day nutrition is that nothing new goes in your body on race day. Not a new gel flavor. Not a new breakfast food. Not a different electrolyte drink. Not more caffeine than usual.
Your training runs are not just for building fitness. They are also for testing and refining your fueling strategy so that on race morning, you are executing a plan you already know works for your body. Use your long runs to experiment with timing, products, and amounts. Treat your two or three longest training runs as dress rehearsals for race day nutrition.
The runners who struggle nutritionally on race day are almost always the ones who figured they would sort it out when they got there, or who followed generic advice without testing it first. The runners who feel strong at mile twelve are the ones who did the work in training to know exactly what their body needs and when.
If you are not sure where to start, or if you have had fueling problems in past races that you have not been able to figure out on your own, that is exactly the kind of problem a sports dietitian is there to help with. Your nutrition plan should be as individualized as your training plan.
Training for a half-marathon and want a fueling plan built for your body and your race? A free connect call is the place to start.
Frequently Asked Questions
Do I need to fuel during a half-marathon if I run it in under two hours?
Yes. You will need to fuel here. Anything over 75-90 minutes long will require fuel mid-race to maintain liver glycogen and ensure that blood glucose doesn’t get low.
What should I eat the night before a half-marathon?
A familiar, carbohydrate-rich dinner that you have eaten before without any digestive issues. Pasta with a simple tomato sauce, rice with lean protein, or a potato-based meal all work well for most runners. Keep fat and fiber moderate, avoid anything spicy or unfamiliar, and eat earlier in the evening rather than late so you are not still digesting when you try to sleep. The night-before meal matters less than the overall carbohydrate intake across the two to three days before your race.
I get stomach problems during races. What is causing it, and what should I do?
The most common causes are taking in too much carbohydrate too quickly, using products you have not trained with, running harder than your gut is adapted to, not training with increased intake in training, dehydration, eating fueling products with fiber/fat, or pre-race anxiety affecting your digestion. Start by reviewing what you are taking in and when, and make sure everything you use on race day has been tested thoroughly in training. If GI issues persist despite addressing those factors, working individually with a sports dietitian is the most direct path to figuring out what is going on.
Can I use real food instead of gels during a half-marathon?
Yes, though it requires more planning. Dates, banana pieces, dried mango, or rice-based options can all work as mid-race fuel. The practical challenge is that real food takes longer to digest, is bulkier to carry, and can be harder to eat at race pace. If you prefer real food over commercial gels, that is a completely valid choice, but test it extensively in training to make sure your gut handles it at race effort before committing to it on race day.
How much should I eat after a half-marathon?
More than you think. Most runners underestimate how much their bodies need in the 24 to 48 hours following a race. In the immediate window after finishing, aim for a meal or snack with both carbohydrates and protein within an hour. After that, eat normal, consistent meals and do not restrict because you are no longer in heavy training. Your body is repairing muscle tissue and restoring glycogen for days after a race, and it needs adequate fuel to do that well. How quickly you recover physically is directly related to how well you eat afterward.und