Fuelling guides
The reasoning behind the numbers. Every guide here is the same material the app uses to build your targets, written out properly — no supplement marketing, no hedging, and sources named where the evidence matters.
How many carbs per hour do you need?
Your gut, not your stomach, sets the ceiling — around 60g an hour from glucose alone, up to 90g once fructose is in the mix. What to aim for by session length, and why spacing beats dosing.
How much should you drink while training?
Replacing every litre you sweat is out-of-date advice and carries real risk. Why losing 2% of your body mass is fine, and how to measure your own sweat rate in a single session.
How much sodium do you actually need?
Sweat sodium varies tenfold between athletes, which makes generic electrolyte advice close to useless. How to tell whether you're a salty sweater, and what potassium and magnesium are really worth.
What to eat after training
The 30-minute window matters far less than you've been told — unless you're training again tomorrow. What carbohydrate, protein, fluid and sodium each actually do afterwards.
Or skip straight to your numbers
Enter your sport, duration, intensity and weight. My Fuel Plan gives you carbohydrate, fluid and sodium targets per hour, and what to take to hit them.
Calculate my fuel planFree to use. No account needed to see your numbers.
More inside the app
The Fuel IQ section of the app goes further than these four guides — race day timing, carb loading and caffeine protocols, gut training to raise how much you can absorb per hour, what to do when things go wrong mid-session, and a searchable library of carbohydrate and protein values for common foods and products.