Feed zone

Fueling planner

A stop-by-stop plan for your gran fondo: how much to drink, how many grams of carbs, how much sodium and when to take caffeine, worked out for every feed station.

Built from your ride time, weight, sweat profile and the temperature on each leg.
Turned into things you actually carry: bottles, gels and bars.
Prints on one page for your pocket or top tube.
Every number is explained, with the research behind it.

Example race · Alpine loop · Saturday 14 June 2025

An example plan

The example race: the Alpine loop at the pace pacing predicts, a 72 kg rider aiming for 80 g of carbs an hour, a stop at each of its four feed stations, each leg at the temperature forecast there and then.

FondoLab fueling plan · 8h47 ride · 72 kg rider · 80 g/h carbs · average sweater, average sweat · caffeine: medium sensitivity

8h47 ride · 5 fueling places · take on each amount to cover the leg to the next stop.

Feed zone Ride totals

Carbs: 703 g
Per hour: 80 g/h
Fluid: 7.6 L
Sodium: 6056 mg
Caffeine: 325 mg

Projected fluid deficit 3.5% of body weight Too high Why?

You'll sweat ≈ 10.12 L and drink ≈ 7.57 L (avg 862 ml/h) — hot legs capped at your 1 L/h drinking limit. Leftover loss ≈ 2.55 L. Aim to stay under 2–3%; start well hydrated.

80 g/h needs a 2:1 glucose:fructose mix. Why?

Whole ride: 10 × 750 ml bottles of mix (400 g of mix powder) · 12 gels

Stop by stop

At each stop: what to grab, and how much of it to take before the next.

Start 0:00
Start with
- 2 × 750 ml bottles of mix
- 4 gels
= 180 g carbs (plan 172 g)
Fluid
1.50 L

Carbs
172 g

Sodium
1204 mg
560 mg/h

Caffeine
165 mg
- first gel at the gun (or first 10 min) — start fueling from km 0, not 15–45 min before
- 165 mg early lift — swallow ~45 min before the start so it peaks as you roll out
2h09 0:00 → 2:09 19°C · sweat 0.9 L/h
1
Col du Glandon 2:09
Grab here
- ½ × 750 ml bottle of mix
- 1 gel
= 51 g carbs (plan 47 g)
Fluid
480 ml

Carbs
47 g

Sodium
385 mg
660 mg/h

Caffeine
–
35 min 2:09 → 2:44 23°C · sweat 1.1 L/h
2
Saint-Michel-de-Maurienne 2:44
Grab here
- 2½ × 750 ml bottles of mix
- 2 gels
= 153 g carbs (plan 165 g)
Fluid
1.94 L

Carbs
165 g

Sodium
1550 mg
750 mg/h

Caffeine
–
2h04 2:44 → 4:48 26°C · sweat 1.2 L/h
3
Valloire 4:48
Grab here
- 3 × 750 ml bottles of mix
- 3 gels
= 188 g carbs (plan 196 g)
Fluid
2.11 L

Carbs
196 g

Sodium
1690 mg
690 mg/h

Caffeine
–
2h27 4:48 → 7:15 24°C · sweat 1.1 L/h
4
Bourg d'Oisans 7:15
Grab here
- 2 × 750 ml bottles of mix
- 2 gels
= 132 g carbs (plan 123 g)
Fluid
1.53 L
gut-capped

Carbs
123 g

Sodium
1227 mg
800 mg/h

Caffeine
160 mg
- collect 160 mg here, then swallow at 7:32 (~75 min before the line)
1h32 7:15 → 8:47 28°C · sweat 1.4 L/h
Finish 8:47

Done: recover with food and drink.

Projected fluid loss exceeds 3% of body weight — add a cooling/drink stop, pre-hydrate, or expect performance to fade in the heat.

Above 60 g/h you need BOTH glucose and fructose. The glucose transporter (SGLT1) saturates at ~60 g/h (~1 g/min); fructose crosses on a separate channel (GLUT5) worth another ~30–60 g/h. A single-sugar drink past 60 g/h just pools in your gut and causes distress — switch to a ~2:1 glucose:fructose mix.

A planning guide, not a prescription: numbers are population-based estimates. Practise your race fueling in training. How this is calculated, with sources.