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What to Eat Before
a Half Marathon

February 2026 Race Strategy 7 min read

My first half marathon I ate a massive pasta dinner the night before, woke up at 5 a.m. and forced down a bagel I didn't want, took zero gels during the race, and hit the wall so hard at mile 9 that I had to walk a full minute. I finished. I also learned more about race nutrition in those final four miles than in all my training runs combined.

Fueling for a half marathon is simpler than most runners make it — but getting it wrong is expensive. Here's what actually works, built around four years of racing and a lot of trial and error.

A half marathon takes most runners between 1:40 and 2:30 to finish. That's long enough that what you eat in the 24 hours before — and what you take mid-race — has a real, measurable impact on how the final 5K feels.

The Full Timeline

When
What to Do
2 Days Out
Start eating slightly more carbohydrates than normal. Not a full carb-load — that's a marathon strategy. Just shift your plate toward rice, pasta, or potatoes and away from heavy fats and high-fiber vegetables. Avoid introducing any new foods. This is not the week to try the Thai place.
Night Before
A moderate carb-heavy dinner, eaten early enough to digest fully. Rice and chicken, pasta with a light sauce, or whatever your body knows well. Portion is normal — not a feast. The pasta myth: a huge dinner the night before doesn't load glycogen, it just sits in your gut. Eat normally, eat early, sleep well.
Race Morning
90–120 minutes before the gun: 300–500 calories of easily digestible carbs. Toast with peanut butter and banana, oatmeal, a bagel with honey. Coffee if that's your routine — don't skip it on race day. Whatever you eat, you must have eaten it before a long training run. Race morning is not an experiment.
30 Min Before
Optional: a small additional carb hit if your stomach tolerates it. Half a banana, a few dates, a small gel. Some runners skip this entirely — know your gut. Hydrate steadily through the morning. You should arrive at the start already fully hydrated, not scrambling to catch up.
Mile 5–6
First gel or chew. Take it before you feel like you need it — by the time you feel the deficit, you're already behind. 45–60mg of caffeine here is a meaningful performance aid for most runners. Chase it with water at the next aid station, not a sports drink — the combination can cause GI issues.
Mile 9–10
Second gel if your race is longer than 1:45. If you're sub-1:45, you may be fine on one. If you've ever walked the final 5K of a half, you needed this gel and didn't take it. This is where the race either holds together or doesn't. The gel doesn't save a bad race — it protects a good one.

The Gear Page Reality

Not all gels are equal and your stomach will let you know. The two I've run on and trust are on the Gear page — Science in Sport Beta Fuel uses a 2:1 maltodextrin-to-fructose ratio that genuinely absorbs faster with less GI distress, and Maurten's hydrogel technology goes down smoother than anything else I've tried. If you've had stomach issues with standard gels, both are worth testing in training before race day.

The non-negotiable rule: test every gel you plan to race on during a long run first. Mile 9 of a half marathon is the worst possible moment to discover your stomach doesn't tolerate a particular brand.

Five Rules That Hold Across Every Race

  • 01
    Nothing New on Race Day Not your shoes, not your breakfast, not your gel brand. Every variable you introduce is a variable that can go wrong. Race day is not the time to find out your stomach doesn't like a new flavor.
  • 02
    Eat Before You're Hungry, Drink Before You're Thirsty Hunger and thirst are lagging indicators mid-race. By the time your body signals either, you're already behind. Proactive fueling — gel at mile 5 whether or not you feel like you need it — is the whole game.
  • 03
    The Night Before Matters Less Than You Think Your glycogen stores are built over the preceding 48 hours, not a single meal. The pre-race dinner is maintenance, not loading. Sleep matters more than what's on the plate.
  • 04
    Pre-hydrate the Day Before, Not the Morning Of Drinking large amounts of water race morning just means extra bathroom stops at the start. Consistent hydration through Friday — including electrolytes — means you arrive Saturday already topped up. Liquid I.V. or any quality electrolyte mix the evening before is worth the habit.
  • 05
    Caffeine Works — Use It Strategically Caffeine is one of the most well-researched legal performance aids in endurance sport. If you're a regular coffee drinker, don't skip it race morning. A caffeinated gel at mile 5 adds a meaningful second boost. Just don't introduce caffeine in a gel for the first time mid-race if you've never tested it.

If You're Running Your First Half

Keep it as simple as possible. A breakfast you've eaten before long runs, one gel around mile 6, and consistent water at aid stations will get you through. Most first-timers aren't racing a time — they're finishing — and the nutrition demands for a 2:15 half are lower than for a 1:50 one. Build your fueling protocol over multiple races, not all at once.

The Taper Calculator includes race week field notes that cover hydration and sleep alongside mileage — worth running before your first race to see the full picture in one place. And if you're trying to figure out what pace to hold so the wheels don't come off in the first place, the Pace Calculator is the tool I actually use mid-race.

Bottom Line

Race day nutrition isn't complicated — it just requires discipline and practice. Eat what you know, earlier than feels necessary, and take that second gel even when mile 9 feels fine. It won't feel fine at mile 11 if you didn't. The runners who blow up in the final 5K almost always made a fueling decision earlier in the race that sealed their fate. Don't be that runner.