Personalised Fuelling Planner for Runners, Cyclists and Triathletes

The science behind your plan

How the fuel planner works

Every plan is built from the same rules: duration sets your carbohydrate range, intensity places you inside it, and conditions and bodyweight set your sodium. Here is what that means in practice.

How many energy gels do I need for a marathon?

It is set by your finish time, not by the distance. A gel carries a fixed amount of carbohydrate, so the number you need is your hourly carbohydrate target multiplied by the hours you will be out there. Two runners covering the same 42.2 km an hour apart need different plans.

Enter your goal finish time in the planner above and it returns the gel count, the spacing between them, and the flavour split.

How many carbs per hour should I take?

Your event duration sets the range, and your intensity places you inside it. Short and easy sits at the low end; long or hard sits at the top, because you are burning through stored carbohydrate faster and have longer to run out of it.

The planner works this out from your finish time and effort level rather than applying one number to everybody.

How much sodium do I need per hour in the heat?

Heat raises sweat sodium losses, so the conditions you expect set your sodium-per-hour bracket. Bodyweight matters too: above roughly 75 kg the target shifts to the top of the range.

Where your gels alone do not cover the target, the plan tells you how much more sodium to add and which electrolyte covers it.

How is my fuelling plan calculated?

It is a rule-based calculation, not a guess. Your distance and goal finish time give the event duration, which sets the carbohydrate range. Intensity moves you within that range. Conditions and bodyweight set the sodium bracket. Cramp history and your caffeine preference then decide what is added on top.

Nothing is stored and no account is needed — the answers are used to build the plan and nothing else.

Does pickle juice actually help with cramp?

It works through a fast neurological reflex triggered in the mouth and throat, not by replacing electrolytes — which is why the effect arrives far sooner than anything swallowed could be absorbed.

Tell the planner you cramp during long efforts and it builds shots into the plan. If you do not, it offers them as an optional add-on instead of forcing them into your cart.

Should I use caffeine gels, and when?

Caffeine is a preference rather than a requirement, so the planner asks before including it. Eltane coffee gels carry 75 mg each and are placed in the closing third of the event, where the lift is worth most.

Answer no and your plan uses caffeine-free flavours only.

Does the planner work for cycling and triathlon?

Yes. Cycling uses the same distance and finish-time pair as running. Triathlon asks for a target time per discipline instead — swim, bike and run — because the three legs do not fuel the same way and a single combined time hides that.