Guidelines for the 1–3 days before events over 90 minutes.
Portions use everyday reference amounts (1 cup cooked rice ≈ 45g carbs, 1 slice white bread ≈ 15g, 1 banana ≈ 27g). Swap foods freely — the grams are what matter. Keep fibre and fat low, keep foods familiar, and drink to thirst; loaded glycogen stores water, so a kilo or two on the scale is normal and temporary.
Guidelines for events over 90 minutes: 8–12 grams of carbohydrate per kilogram of body weight per day, for 1–3 days before the race. Daily totals by body weight:
| Body weight | 8 g/kg (lighter) | 10 g/kg (full) | 12 g/kg (maximum) |
|---|---|---|---|
| 55kg / 121lb | 440g | 550g | 660g |
| 60kg / 132lb | 480g | 600g | 720g |
| 65kg / 143lb | 520g | 650g | 780g |
| 70kg / 154lb | 560g | 700g | 840g |
| 75kg / 165lb | 600g | 750g | 900g |
| 80kg / 176lb | 640g | 800g | 960g |
| 90kg / 198lb | 720g | 900g | 1080g |
Worked example: a 70kg runner loading at 9 g/kg needs 630 grams of carbohydrate in the day — roughly the equivalent of 14 cups of cooked rice if it came from one food, which is why the plan above spreads it across six smaller, low-fibre meals instead.
A proper load is less about one giant pasta dinner and more about steady, low-fibre carbohydrate across the whole day — six eating occasions rather than three heavy ones. Spreading the grams keeps digestion comfortable and glycogen synthesis topped up, which is exactly why the plan above leans on white rice, bread, juice, bananas and simple sweets rather than wholegrains and salads. Save the vegetables for after the race.
Evidence-wise, elevated carbohydrate intake in the 36–48 hours before endurance events reliably raises muscle glycogen, and higher pre-race intakes are associated with faster marathon times. The full background — including what to eat on race morning — is in our guides to carb loading for the half marathon and fuelling a long run.
When should I start? 1–3 days out. Muscle glycogen maximises within 36–48 hours of high intake alongside a taper — a week-long load adds nothing but gut stress.
Why am I heavier after loading? Every gram of glycogen stores ~3g of water, so 1–2kg on the scale is normal, temporary, and an advantage — it’s fuel and hydration, not fat.
Do I still need breakfast on race morning? Yes — a lighter 1–2 g/kg of familiar carbs 2–4 hours before the start tops up liver glycogen that depletes overnight. The load fills the muscles; breakfast refills the liver.
Racing in heat? Price the conditions with the heat-adjusted pace calculator.
Kovr moves these targets for you — automatically.
Tell Kovr your race and it ramps your carb target through race week, adjusts it to your training each day, and tracks the load in hand portions as you log by voice. On race eve, the fuel ring already knows what the day demands.
Download Kovr on the App Store