Most bad races aren’t fitness failures, they’re fuelling failures. The plan itself is simple: take in carbohydrate at a steady rate, drink to thirst with electrolytes, and rehearse the whole thing in training so race day is a repeat, not an experiment.
Carbohydrate per hour
Your working muscles run mostly on carbohydrate, and your own stores only cover a couple of hours of hard effort. Anything longer means taking carbohydrate in while you move.
Common guidance for endurance events is roughly 30–60g of carbohydrate per hour, with well-trained athletes going higher on longer events when they’ve deliberately trained the gut to handle it. Products combining glucose and fructose absorb through more than one pathway, which is how the higher intakes become tolerable at all.
Start feeding early. Waiting until you feel empty means eating from a deficit for the rest of the race, and by then your stomach is far less cooperative.
Drink mix, gels or solids?
There’s no single right answer, only what your gut accepts at race pace. Drink mixes handle fuel and fluid together and are easiest to keep to a rhythm. Gels are compact and precise. Real food and bars sit better for some people over very long, slower events.
The practical approach is a base of carbohydrate drink for consistency, plus something chewable to break the monotony on longer efforts. Sweet-fatigue is real, and a race is a long time to drink only one flavour.
Fluid and electrolytes
Sweat rates vary enormously between people and with heat and humidity, so a universal millilitres-per-hour figure is worthless. Drink to thirst and keep it regular rather than gulping at every table.
Include sodium, especially in South African heat and on anything over a couple of hours. It’s what lets the fluid actually stay with you. Over-drinking plain water on a long, hot day is a genuine risk, not just a discomfort.
Caffeine timing
Caffeine works, and it works best used deliberately rather than continuously. Save it for the part of the race where concentration and effort start slipping — typically the last third.
Test your dose in training. Caffeine sensitivity varies wildly, and the wrong amount at the wrong moment gives you a racing heart rate and an unhappy stomach instead of a lift.
Rehearse it — this is the part people skip
Your gut is trainable, and it needs the practice as much as your legs do. Use your long runs to run the exact plan: the same products, the same flavours, the same intervals, at close to race pace.
Write the plan down as a simple schedule — what you take, when, and where it’s coming from. Know which aid stations you’re using and what you’re carrying. Then on race day you’re executing something familiar.
One iron rule: never take anything new on race day. Not a new flavour, not the free sachet in the goodie bag, not what your mate swears by.
A simple starting framework
For a first marathon or long trail race: begin fuelling within the first 30–45 minutes, then keep to a fixed interval you can remember without thinking. Sip regularly rather than drinking in bursts. Bring caffeine in late. Adjust the amounts over a training block based on how your stomach actually responds — not on what a faster runner does.
Fuel early, keep it boring, and never trial anything new on race day.
Got a question this didn’t answer? Email info@pureendurance.co.za.