Carb loading for a HYROX is two days of eating more carbohydrate and less fibre. It is not one enormous dinner the night before, which is the version most people do and the version that most often backfires.
The single most useful sentence on this page: the night before matters less than the two days before it, and fibre coming down matters almost as much as carbohydrate going up.
Why trust this
A HYROX is roughly 60 to 110 minutes for most people, which is long enough for glycogen to matter and short enough that a full marathon-style protocol is overkill. The distances are fixed by the 26/27 rulebook, so unlike a marathon the duration band is fairly predictable, which makes this easier to plan than most endurance events.
Ben Sutherland races Pro Doubles on the Elite 15 start list.
The two-day plan
| When | Carbohydrate | Fibre | Notes | |---|---|---|---| | 48 hours out | Up to around 7-8 g/kg | Normal | The day that does most of the work | | 24 hours out | Same again | Cut it back | White rice over brown, ripe fruit over salad | | Night before | Normal-sized meal, carb-heavy, familiar | Low | Do not eat until you are uncomfortable | | Race morning | 1-2 g/kg, 2-3 hours before your wave | Minimal | Nothing new. Nothing you have not trained on |
For a 75kg athlete, 7-8 g/kg is roughly 525 to 600g of carbohydrate a day. That is a genuinely large amount, and realising that on the evening before is exactly why it has to start two days earlier.
Why fibre comes down as carbohydrate goes up
This is the part people miss, and it is the one that actually ruins races.
Eating substantially more food while keeping your normal fibre intake means arriving at the start line with a full gut. The Roxzone is not the place to discover this. In the last 24 hours, swap the wholegrains for white versions, ripe fruit for raw vegetables, and skip the enormous salad you would normally be proud of.
You are not eating badly for a day. You are eating for a specific job.
The mistakes that cost more than the loading gains
Trying it for the first time on race week. Every part of this should have been rehearsed in training, ideally before your longest session. Race week is not the time to find out that a particular breakfast does not agree with you.
Loading while still tapering, and gaining nothing. Carbohydrate stored with water, so you may be a kilogram or two heavier. That is normal, it is not fat, and it is not a reason to cut back.
One huge dinner. Late, large and unfamiliar is a recipe for bad sleep, and a bad night's sleep costs you more than the glycogen gains you.
Forgetting salt. If you have been training hard and sweating, going into a race with topped-up carbohydrate and depleted sodium is an odd trade. A normal amount of salt on food across those two days is enough for most people.
Under-eating all taper week, then loading. Volume drops in a taper and appetite often drops with it. Arriving at the 48-hour mark already low is the most common reason people feel flat despite "loading".
The practical part
- Work out your number. Body weight in kg times 7, and again times 8. That is your daily range for the final two days.
- Plan the meals, do not improvise them. Write down what you will eat and buy it before race week starts.
- Rehearse the race-morning meal at least twice in training, before a hard session.
- Drop fibre from 24 hours out, not 48. You do not need two days of it.
- Eat a normal-sized dinner the night before. Familiar, carb-heavy, early enough to sleep on.
- Race morning: 2 to 3 hours before your wave, 1 to 2 g/kg, and nothing you have not eaten before a session.
Honest limitations
These numbers are the commonly used ranges, not a personalised prescription, and individual tolerance varies a lot. Some people race well on considerably less.
If you have diabetes, a gut condition, or any medical reason to manage carbohydrate carefully, this page is not written for you and the plan is a conversation with a professional.
And the real hierarchy is worth saying plainly: twelve weeks of consistent training, then sleep, then general eating, then this. Carb loading is a small edge applied to a big foundation. It cannot rescue a block that did not happen.
Next step
The two days before a race only matter if the twelve weeks before them did. The HYROX training plans build the block this page assumes, counting back from your race date.
The fitness assessment quiz tells you where you are starting from.
Related
- HYROX 12-week nutrition timeline: the whole block, phase by phase.
- HYROX macros: how much protein, carbohydrate and fat you actually need.
- What to eat before, during and after a race.
- HYROX taper week protocol, which is the week this sits inside.
[ FAQ ]
Frequently asked
Do you need to carb load for a HYROX?
For a race around 60 to 110 minutes, a full marathon-style load is not necessary, but topping up glycogen across the last 48 hours is worth doing and costs you nothing. The bigger win is not arriving under-fuelled after a week of tapering while still eating like you are training.
How many carbs should you eat before a HYROX?
Around 7-8 g per kg of body weight per day across the final 48 hours is the usual range for a full top-up. For a 75kg athlete that is roughly 525-600g a day, which is more than most people expect and is the reason it has to start two days out.
Should you eat pasta the night before a HYROX?
You can, but the night before is the least important meal of the three. Most of the loading should already have happened, and a huge late dinner is more likely to disturb your sleep than help your race.
Written by
The Suth Performance teamCoaches and editors
The Suth Performance programming team, led by HYROX Elite 15 athlete Ben Sutherland. They write the training, technique and race-day guides on this site, and Ben reviews every one before it is published.
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