The night before the race, half the field sits down to an enormous bowl of pasta and calls it carb-loading.

It has become a ritual — almost a superstition.

And as a way of actually filling your glycogen stores, it mostly doesn’t work.

Why one big dinner can’t do it

Muscle glycogen is your body’s stored carbohydrate, and there is a limit to how fast it refills. Supercompensating those stores requires sustained high carbohydrate intake spread across a day or two, not a single sitting.

One large pasta dinner runs into two problems at once. It arrives too late to matter for a next-morning start, and it delivers far less carbohydrate than a genuine load requires. What it reliably produces is a heavy, over-full gut on the start line — the opposite of what you were after.

Intuitive and reassuring are not the same as correct.

What a real load looks like

For events lasting longer than about 90 minutes, the widely cited guidance is to raise carbohydrate intake to roughly 10 to 12 grams per kilogram of body weight per day, for around 36 to 48 hours before the event, alongside a training taper.^[1]

Those numbers are deliberately not restated as a plate of food here, because the point of a load is that it is calculated, not estimated by eye. Our Race-Day Fuelling Calculator converts your body weight and event duration into the actual daily gram target.

Once you calculate the target, one thing becomes immediately obvious: a true load is a large, deliberate, sustained effort across meals — nothing like a single bowl, however big.

The part the myth gets backwards on timing

The old 1960s protocol demanded a week of glycogen-depleting exercise — miserable, and largely unnecessary for most. Research has since shown that well-trained athletes can supercompensate far faster: a single day of high carbohydrate intake with rest was enough to reach supercompensation within 24 hours in trained participants.^[2]

Because trained muscle has chronically higher glycogen-storage machinery, the practical window for many athletes is closer to 24 to 36 hours than a full two days.^[2] But note what both ends of that range share: they are measured in days of sustained intake, and the night-before dinner sits outside both.

When you shouldn’t bother at all

For efforts under about 90 minutes, a normal carbohydrate-containing diet and a good pre-race meal already provide enough glycogen — loading just adds water weight and gut load for no benefit.^[1] A parkrun does not need loading. A marathon does. The event decides, not the occasion.

Where honey fits in a load

A carbohydrate load is built mostly from ordinary low-fibre, familiar foods — rice, bread, pasta, potatoes, fruit. Honey is a useful contributor: a simple, low-fibre carbohydrate source easy to add to the extra intake a load requires without adding bulk or fat. It is a part of the day’s total, not a shortcut that replaces it. No single food does the loading for you.

Getting it right instead

Decide first whether your event even warrants a load — over about 90 minutes, yes; under it, no. If it does, work out your daily gram target with the Race-Day Fuelling Calculator, begin a day or two out rather than the night before, lean on low-fibre familiar foods, and taper your training so the carbohydrate goes into storage rather than being burned in a hard session. Reducing training load during the loading window means more of the incoming carbohydrate can be stored as glycogen rather than being immediately oxidised in hard exercise — which is the whole point of loading in the first place.

Then treat the immediate pre-start window as its own separate task — covered in The Pre-Load Protocol.