Race-Day Fuel: Gels, Drinks, and What to Eat When

Every distance-running disaster story features one of two characters: the runner who ate nothing and hit the wall at 30 km, or the runner who tried a free expo gel at 25 km and met every portaloo on the course personally. Fueling is simple to describe and easy to get wrong, so here's the simple version, with the traps marked.

The golden rule

Nothing new on race day. Not the gel, not the drink, not the magic pre-run porridge your cousin swears by. Everything you plan to consume in a race gets rehearsed on long club runs first, several times, at race effort. Your stomach is a trainable organ — and an untrained one holds grudges.

Before: breakfast is just a top-up

The fuel for a morning race was mostly banked at dinner. Breakfast, 2–3 hours out, is simple familiar carbs and not much else: toast and honey, porridge, a banana, white rice — low fibre, low fat, low drama. Coffee if coffee is normal for you (for most runners it genuinely helps; caffeine is the most evidence-backed legal performance aid there is). Then stop eating an hour out, sip water, and trust the taper.

During: the carbs-per-hour math

Under an hour (5K, 10K for most people): you need nothing. Water at most. Anyone selling you fuel for a parkrun is selling you something.
60–90 minutes: roughly 30g of carbs per hour — one gel, or sports drink, taken before you feel like you need it.
90 minutes to 3+ hours (half and full marathon): 60g per hour, and modern practice pushes trained stomachs toward 90g with dual-source (glucose+fructose) products. That's a gel every 25–30 minutes — far more than intuition suggests, which is exactly why you practise it.

On brands: GU and SIS are the everywhere-standards; Maurten's hydrogel formulas are the premium race-day favourite for sensitive stomachs; SIS Beta Fuel and similar dual-source options carry the 80–90g/h loads. They're genuinely different in texture and sweetness — thick vs pourable, dessert-sweet vs mild — so buy singles of several and audition them on long runs before committing to a race stash.

Hydration and salt

Thirst is a good coach for anything under two hours in mild weather. Beyond that — or in heat — add electrolytes: tablets like Nuun in a bottle, a mix like Skratch, or the salt already in many gels. The classic mistake isn't drinking too little, it's drinking plain water in volume during a hot marathon and diluting yourself into cramps. If your club does summer long runs, practise your drink plan there; see what the aid-station cups do to your pace and your stomach at speed.

After: the boring window

Within an hour or so: carbs to restock, protein to repair — chocolate milk remains the unbeatable budget recovery drink, and the club's post-run café stop is a legitimate training protocol. The beer garden variant works too; alternate pints with water and future-you says thanks.

The cheat sheet

Rehearse everything on long club runs; race day is a dress rehearsal's opening night.
Under an hour: water. 60–90 min: ~30g carbs. Longer: 60–90g per hour, practised.
Take the first gel early — at 40 minutes, not when you fade. You're fueling kilometre 35 at kilometre 10.
Heat = electrolytes, not just water.
Caffeine works; new-on-race-day anything doesn't.