Race-day nutrition is one of the most over-complicated topics in distance running. The underlying science is genuinely simple: your muscles run primarily on stored carbohydrate (glycogen) during race-effort running, that store is limited to roughly 90-120 minutes' worth at marathon effort, and eating strategy exists to top up that store beforehand and slow its depletion during the race. Everything else is detail.
This is general, well-established sports-nutrition guidance — not medical advice, and not tailored to any specific health condition. If you have a medical condition that affects diet, talk to a doctor or dietitian rather than following generic guidance.
The 2-3 days before the race
This is when genuine carbohydrate loading happens — not the two-week taper, just the final 2-3 days. The goal is to maximize glycogen stores in muscle and liver before you start burning through them on race morning.
- Gradually shift the balance of your meals toward carbohydrates — rice, pasta, bread, potatoes, oats — without dramatically increasing total calories, since you're also tapering and burning less.
- Keep meals familiar. This isn't the moment to try a new cuisine or a very high-fiber diet that your gut isn't used to.
- Stay on top of hydration throughout the days before, not just the morning of — consistent, moderate fluid intake beats a single large volume the night before.
- The often-repeated advice to eat one huge pasta dinner the night before is outdated — a large, unfamiliar meal late the night before can actually disrupt sleep and digestion. Spread the extra carbs across the 2-3 days instead.
Race morning
Eat 2-3 hours before the start if possible — this gives your body enough time to digest so you're not running on a full stomach, while still topping up liver glycogen that's depleted overnight during sleep.
| Good race-morning choices | Why |
|---|---|
| White toast/bagel with honey or jam | Carb-focused, low fat, low fiber — digests quickly and predictably. |
| Porridge/oatmeal made with water or a small amount of milk | Reliable, familiar, easy on the stomach for most runners. |
| A banana | Easily digestible carbohydrate, plus a little potassium. |
| Sports drink or diluted juice | Tops up fluids and carbs together without a large volume of food. |
The one rule that actually matters here
Nothing new on race day. Not a new breakfast, not a new gel brand, not a new energy drink — even if a fellow runner swears by it. Anything you put in your body on race morning or during the race should already have been tested, ideally more than once, during a long training run.
Foods to avoid or minimize on race morning: high-fiber cereals, large amounts of dairy if you're at all sensitive to it, greasy or high-fat foods, and anything genuinely new. All of these raise the risk of GI distress mid-race, which ends more marathons early than pacing mistakes do.
Fueling during the race
For races under about 75-90 minutes (most 10Ks and faster half marathons), on-course fueling generally isn't necessary — your existing glycogen stores are enough. For anything longer — most half marathons and all marathons — a general, widely-cited guideline is roughly 30-60 grams of carbohydrate per hour once the race passes that 60-90 minute mark, via gels, chews, or on-course sports drink.
- Start fueling before you feel like you need it — once you're genuinely bonking, it's harder to recover from.
- Take gels with water where possible, since concentrated carbohydrate without fluid can be harder to absorb and sit poorly.
- Space gels out rather than taking two at once, even if you're behind on your fueling plan — your gut can only process carbohydrate at a certain rate regardless of how much you've consumed.
- If a race's own water/gel stations are unpredictable or unconfirmed (check the specific race's own page for this), carry your own to avoid being caught out.
After the race
A mix of carbohydrate and protein within the first hour or so after finishing supports recovery — this is a genuinely well-supported principle in sports nutrition, not a fad. It doesn't need to be complicated: a recovery shake, a sandwich, or a normal meal with both carbs and protein all work. What matters more than the exact source is not skipping refueling for hours simply because you don't feel hungry immediately after finishing.