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How to Set Up a Race-Week Nutrition Plan

Stephen M. Walker II • April 3, 2026

A runner shows up to a spring marathon after a textbook training block. She tapered well, hit every long run, and felt ready. Then race week happened. She ate "clean" through Friday, skipped real carbohydrate loading because the food volume felt excessive, drank a liter of plain water at 5 a.m. because a friend said to, and swapped her usual oatmeal for a hotel buffet egg scramble because her stomach felt off. By mile 18 she was light-headed, cramping, and 12 minutes off pace. Nothing failed during the race. Everything failed before it.

Race-week nutrition comes down to four controllable variables: enough glycogen, enough fluid, enough sodium, and a breakfast you have already tested under training stress. Nail those four and race morning becomes the calmest part of the whole block.

Start with the event you are actually doing

A 10K, marathon, half-Ironman, and Ironman each place different demands on your fuel stores. The right race-week plan starts with event duration, intensity, climate, and your likely carbohydrate intake during the race.

Quick decision guide. Find your expected finish time below and use it to decide how aggressively to plan.

• Under 90 minutes. Glycogen stress is moderate. Eat normally through race week. Focus on a controlled pre-race meal and adequate hydration. Full carbohydrate loading is unnecessary. Start with breakfast and fluid planning below.
• 90 minutes to 3 hours. Glycogen stress is high. You need a structured loading window, a rehearsed breakfast, and a basic fluid plan. Start with the loading window and breakfast below.
• 3 to 6 hours. Glycogen and hydration stress are both very high. Add a sodium plan, an aid-station script with specific products and timing, and gut-tested race nutrition. Read every section below and build from the half-Ironman example plan.
• 6 hours and beyond. Total intake stress is extreme. Layer everything above with pacing-aware intake targets, backup feeding plans, and fluid and sodium guardrails that account for changing conditions across the day. Read every section below and build from the ultrarunner example plan.

Burke and colleagues have shown for years that carbohydrate availability should match the work demand, with longer events requiring both higher pre-race glycogen and higher during-race carbohydrate delivery.¹² A race-week plan is where those targets become an actual schedule.

The loading window is shorter than most people think

You do not need a mythical week of pasta dinners. The old protocol of depleting glycogen with exhaustive exercise before loading has also been retired. Modern research shows that 36 to 48 hours of high carbohydrate intake paired with a taper or reduced training volume produces the same storage levels without the misery of a depletion phase.¹³

The classic target is 10 to 12 g of carbohydrate per kilogram of body mass per day across that final 36 to 48 hours.¹³ For a 70 kg athlete, that is 700 to 840 g per day.

Why that number matters: trained muscle and liver hold roughly 400 to 500 g of glycogen when fully loaded. At marathon pace, that covers roughly 90 to 120 minutes of running before stores drop to critical levels. That threshold is the wall. Loading exists to push it as far out as your event demands.

The number looks absurd until you stop trying to hit it with clean-eating instincts and start using low-fiber, easy-digesting foods on purpose.

This is where athletes get tripped up by food volume. If you try to load with vegetables, dense whole grains, and lean protein at every meal, you usually get full long before glycogen stores are topped up. Low-fiber starches, sports drinks, rice, potatoes, bread, cereal, pancakes, bagels, applesauce, pretzels, and juice are often the better tools for two days. Health halo foods can wait until after the race.

What 750 g of carbohydrate actually looks like in a day

This is the most useful table in this guide. Screenshot it, print it, or copy it into your race-week note. A sample loading day for a 75 kg athlete targeting 10 g/kg, intentionally simple and low-fiber.

The food choices look monotonous. That is the point. Two days of boring, easy-digesting meals buy you full glycogen stores without the gut distress that comes from trying to hit these numbers with fibrous whole foods.

Expect the scale to climb 1 to 3 kg during the loading window. Each gram of stored glycogen binds roughly 3 g of water, so the weight gain is almost entirely retained fluid and fuel. It will be gone by the finish line.

Protein stays in the plan

Carbohydrate loading does not mean protein disappears. Keep protein steady at about 1.6 to 2.2 g/kg/day during race week, then let carbohydrate expansion come mostly from trimming fat and fiber rather than cutting protein into the floor.⁴

That matters for two reasons. First, your taper does not stop muscle repair. Second, very low protein race-week eating tends to turn into unstable appetite, snack grazing, and a harder time getting back on routine after the event. If you need the larger frame, Endurance Athlete Fueling covers the daily energy model and Leucine Threshold covers why weak protein feedings are easy to misread as adequate recovery.

Lower fiber on purpose

The day before a race is not the time to chase your usual fiber total. Lower-residue eating reduces stool bulk and lowers the chance that a perfect fueling plan gets ruined by bathroom urgency or gut pressure.

Athletes with a history of race-day GI symptoms may need the sharper version of this idea. The Gut Training for Race Nutrition guide covers when a short low-FODMAP approach is worth using and when it is just unnecessary restriction.

Fluid and sodium should be written together

Water and sodium are one topic. Sodium helps retain fluid and supports the sodium-glucose cotransport process that moves carbohydrate and water across the intestine. Overdrinking plain water without sodium is one of the main drivers of exercise-associated hyponatremia.⁵⁶ Most athletes do not need heroic sodium loading. They need a steady plan that fits climate, sweat rate, and race duration.

How to estimate your sweat rate

You can collect useful sweat-rate data from any training session longer than 60 minutes. The process takes two minutes of setup.

1. Weigh yourself in minimal clothing before the session.
2. Track every gram of fluid you drink during the session.
3. Weigh yourself again in the same clothing immediately after.
4. Calculate: (pre-exercise weight − post-exercise weight + fluid consumed) ÷ exercise hours = sweat rate in liters per hour.

Run this test in conditions that resemble race day as closely as possible. A cold morning treadmill run will underestimate losses for a warm outdoor marathon. Two or three tests in similar conditions give you a reliable range. If the resulting sweat rate is above about 1.5 L/h and you notice white salt residue on your kit, you are likely a heavier sodium loser and should plan toward the upper end of the intake range below.

McCubbin's 2025 review on sodium intake for athletes makes the central point clearly. The health and performance issue is the relationship between sodium and water, not sodium in isolation.⁶ In practice, many endurance athletes land somewhere around 300 to 800 mg sodium per hour during longer hot sessions, with some heavy sweaters requiring more after testing.⁶ That is a starting range. The site's Sodium Intake page gives the same range in glossary form. Race week is where you decide which part of that range is yours based on your own sweat data.

The night-before meal needs one job

Dinner the night before should top off glycogen and avoid drama. It does not need to be inspirational.

The common failure pattern is obvious. Huge fat load, large vegetable volume, dessert because the race is tomorrow, and a meal so late that sleep gets worse. If sleep hygiene already becomes fragile before races, early dinner and familiar food help more than any supplement stack.

Breakfast is a dose, not a vibe

The pre-race meal should usually land 3 to 4 hours before the start, with roughly 1 to 4 g/kg carbohydrate depending on race duration, start time, and what you have rehearsed.²⁴ The smaller end fits nervous stomachs and shorter events. The larger end fits long races with early starts and fully tested tolerance.

Examples that usually work include bagels with honey, oatmeal plus banana plus sports drink, pancakes and syrup, rice with eggs, or toast plus jam and yogurt if dairy is already safe for you. The right breakfast is the one that has already survived your longest rehearsal.

The pre-start countdown

The hours between breakfast and the gun are where plans go quiet and nerves fill the gap. A simple countdown removes the guesswork.

• 3 to 4 hours before start. Eat your rehearsed breakfast. This is the main fueling event of the morning.
• 90 minutes before start. If the gap between breakfast and the gun is long, take a small top-up of 20 to 30 g carbohydrate. Half a banana or a few sips of sports drink is enough.
• 15 minutes before start. Optional final top-up if you have practiced it. A single gel or a few swigs of sports drink. Skip this entirely if it has ever caused stomach distress in training.

The goal is steady carbohydrate availability from the moment you wake up through the first kilometers. Rehearse this countdown at least once during a long training session so nothing on race morning feels unfamiliar.

Caffeine only works if the rest of the plan is stable

Caffeine helps endurance performance, but only when it does not wreck the gut or spike anxiety past the point of usefulness. The supported range remains about 3 to 6 mg/kg taken about 60 minutes before exercise, with some athletes using smaller top-ups later in the event.⁴⁸

If you are caffeine-sensitive, do not turn race week into a chemistry trial because someone faster than you takes 400 mg. Caffeine covers the evidence and the sleep tradeoffs. For race week, the useful rule is smaller and tested beats larger and theoretical.

Your course map decides your hourly plan

A race-week plan is incomplete until it accounts for aid stations, bottle handoffs, course temperature, and how often you can actually eat.

This sounds obvious. It still gets skipped constantly. Athletes say they are aiming for 75 g of carbohydrate per hour, then discover their course setup only allows a gel every 35 minutes and inconsistent water access. If that sounds familiar, fix it in training first with carbohydrate periodization and gut training, not on the freeway drive to the race.

One practical trick that pays for itself immediately: set a repeating alarm on your watch every 25 to 30 minutes. When it fires, eat or drink. This removes the mental load of tracking intake during the race and catches the drift that happens when focus shifts to pacing and terrain.

Common race foods by carbohydrate content

Knowing the carbohydrate per serving lets you map your hourly target onto the actual products in your pocket and on the course.

If your hourly target is 60 g, that is two gels and a few sips of sports drink, or one gel plus a banana at an aid station. Working backward from these numbers makes your aid-station plan concrete instead of aspirational.

Three race-week plans

The best way to use this guide is to build a written script for your specific race. Here are three examples that show how the same principles scale across different body sizes, events, and conditions.

70 kg marathoner, 3 h 20 min goal, mild weather

58 kg female half-Ironman athlete, 5 h 30 min goal, warm weather

85 kg ultrarunner, 100 km, 12 hour goal, mixed terrain

Ultra planning diverges from shorter races in one critical way: you will stop wanting to eat. Somewhere around hour 5 or 6, sweet gels become repulsive, your appetite drops, and the temptation is to just stop fueling. The plan below accounts for that by splitting the race into two phases with different food strategies and building in savory fallbacks from the start.

A note on palate fatigue for longer events: after 5 to 6 hours of sweet gels and sports drinks, many athletes lose the ability to stomach another sugary serving. This is predictable and should be planned for. Pack savory alternatives in your drop bags or special-needs bottles before race day. Broth, salted potatoes, plain rice, and flat cola are common fallbacks that keep calories moving in when sweetness becomes intolerable.

Each script is boring on paper. That is the point. Race-week nutrition works best when it feels almost administrative. Build your own version using the targets from this guide, then rehearse the breakfast and during-race feeding at least twice in training before committing to it on race day.

Write this plan down and bring it to the start line. Then be willing to adjust based on what you feel, what the weather does, and what your gut tells you at the halfway mark. A good script gives you a default to follow and a clear baseline to deviate from when conditions shift. The goal is a plan you trust enough to follow and flexible enough to adapt.

The mistakes that cost the most time

Your one next step

The runner at the top of this page did not blow up because she was unfit. She blew up because she walked into race week without a written plan. Do not repeat her mistake.

Open a note right now and fill in every line. Any blank is the part of your plan that still needs work.

1. Your body weight in kilograms.
2. Your loading target in grams of carbohydrate per day for the final 48 hours (body weight × 10 to 12).
3. Your pre-race breakfast with exact foods and gram totals, already rehearsed in training.
4. Your sweat rate in liters per hour from a recent training test in race-similar conditions.
5. The exact products you will carry on race day, what is on course, and your hourly intake target.

Fill this in before taper week starts. Then rehearse the full sequence in your next long session, breakfast included, with the same foods, the same fluids, and the same timing you plan to use on race morning.

You will show up to the start line with a script instead of a guess.