Enter a finish time and body mass. Get a load vs during-race split so a 75-minute half does not copy a 700 g marathon day.
Sports dietitian review pending
Load guidance and during-race grams per hour will appear here.
A half marathon can be 70 minutes or 2:45. Those are different GI and glycogen problems. Burke et al. (2011) and Jeukendrup (2014) still scale carbohydrate to event duration and intake rate. Copying a 10 g/kg marathon load onto a fast half mostly makes you heavy.
This splitter buckets finish time in code, then writes a load line and a during-race line from those buckets. The language model is told not to invent extra numbers.
Key takeaway:
Duration decides the load, not the word marathon. A 75-minute half is not a 700 g day.
A practical split
Under ~90 minutes: practised breakfast, maybe a start-line gel you have used. No marathon-style two-day load.
About 1:30–2:00: raise carbohydrate the day before; plan 30–60 g/h after the first 20 minutes if you have gut-trained it.
Past two hours, or a full marathon: treat the load more like the carb-loading calculator and the belt more like the race fuel planner at 60–90 g/h if the gut is trained.
You do not need two full days of white starch for a fast half. You can still ruin the morning with chili. Check dinner in the night-before dinner builder and breakfast in the breakfast builder. The ~15 g plantbaes.net heuristic is still the working ceiling the night before and morning of if your gut is fussy.
How the numbers are computed
Buckets from finish minutes. Load and during-race sentences fixed in code. One short coaching paragraph from the model, forbidden from adding extra gram counts.
Then check packets SKU by SKU. Being vegan does not change the clock. It still changes which gels are allowed.
Frequently asked questions
Do I need to carb load for a half marathon?
Not like a marathon if you finish under about 90 minutes. Practised breakfast usually covers it. From about 1:30–2:00, raise carbohydrate the day before. Past two hours, treat the load more like a short marathon.
How many gels for a half vs a full?
A 75-minute half may need none beyond breakfast. A 2-hour half often wants 30–60 g/h after the first 20 minutes. A marathon still sits in the 60–90 g/h band if you have trained the gut.
Does fiber advice change for a half?
If you are GI-prone, the same ~15 g plantbaes.net heuristic still helps the night before and morning of. You do not need two full days of white starch for a fast half.
Where do the numbers come from?
Finish time is bucketed in code. Load and during-race lines use published carbohydrate ranges. The language model only writes the coaching paragraph from those lines.
Should vegans fuel a half differently?
The clocks are the same. The food list still has to be vegan and, if you are sensitive, lower fiber. Product status still has to be checked SKU by SKU.
What is the next tool after this split?
Breakfast builder for the morning, race fuel planner for the belt, carb-loading calculator only if the splitter said you need a real load.
I am running a 2:45 half. Is that a marathon load?
Treat duration, not the word half. A 2:45 half is a long glycogen problem. Raise carbohydrate the day before and plan 30–60 g/h on course if you have practised it.
Can I skip gels on a marathon because I skipped them on a half?
No. A 75-minute race and a 4-hour race are different gut and glycogen problems. Recalculate.
Educational content only. Carbohydrate, fiber, iron, B12, and hydration needs vary. Consult a sports dietitian or physician for individualized guidance — especially if you have a GI condition, anemia, or a history of underfueling.
