Race-day fueling planner

What it does

The Race-day Fueling Planner takes your physiology and the race schedule and produces an hour-by-hour fueling plan: how many grams of carbohydrate to take in per hour, how much fluid, how much sodium, mapped against pre-race, in-race, and post-race windows.

URL: /calculators/ then open the Fueling entry. Direct path: /static/calculators/triathlon_fueling_calculator.html. Wizard step 7.

Inputs the form asks for

Body

Height (cm).
Weight (kg).

Conditions

Sweat type (light / normal / heavy / very heavy).
Sweat sodium (mg/L): from a sweat rate test if you have one; otherwise a reasonable default.

Race shape

Race distance: sprint, Olympic, 70.3, full distance, custom.
Race start time (HH:MM).
Swim split (min).
Bike split (min).
Run split (min).

Splits ideally come from the Finish Time Estimator.

Outputs

Pre-race window plan (the night before, breakfast, warm-up).
In-race plan: CHO per hour by leg, fluid per hour by leg, sodium per hour by leg.
Post-race recovery window.

The saved CalculatorResult includes a summary field that the wizard step 7 card displays.

How the planner builds the schedule

It uses race start time and split estimates to lay out a clock for the race.
It scales CHO per hour against body weight and intensity.
It scales fluid and sodium against sweat rate and sweat sodium.
It outputs a per-hour table aligned to the clock.

How to use the output

Treat the per-hour numbers as targets. In practice, athletes take CHO in chunks (a gel every 25 minutes, a bottle of mix every 20 km) rather than literally every hour on the hour. Adjust the schedule to your actual product list and stomach.

When to rerun

When body weight changes meaningfully.
When the projected splits change (rerun finish time first).
When conditions change (hot day raises fluid and sodium targets).
When you change your sweat baseline after a fresh sweat test.