Ultra-distance cycling: how to pace and fuel a 12 to 24 hour ride

To pace an ultra-distance ride of 12 to 24 hours, ride well below the effort you would hold in a gran fondo, keep climbs controlled, and aim to feel easy for the first half. To fuel it, eat steadily every 20 to 30 minutes from the start, mix sports products with real and savory food, and keep eating through the night. Short, planned stops and well-timed caffeine often matter as much as fitness.

Ultra-distance cycling covers everything from 300 and 400 kilometer brevets to 24-hour challenges, long gravel races, and self-supported events. What they share is that no one gets through them on fitness alone. Somewhere past ten or twelve hours, the ride becomes a problem-solving exercise: managing your effort, your stomach, your contact points, and your head, often in the dark. The riders who finish well are rarely the strongest. They are the most patient and the best organized.

The pacing ceiling drops with every hour

The effort you can sustain falls as the duration grows. What feels steady for a four-hour ride is too hard for twelve, and what works for twelve is too hard for twenty-four. Over very long events, your whole-ride average ends up well below what you would ride in a gran fondo, and most of the day should feel conversational.

• Cap the climbs. The early climbs are where ultra rides are lost. Riding them at your usual hard pace spends energy you will badly need later. Pick an effort you could hold for hours, and stick to it even when others go past.
• Ride your own ride. Group riding saves energy on the flat, but only if the pace suits you. Chasing a faster group for an hour can cost you far more later on.
• Expect your heart rate to drift. Over many hours, heart rate creeps up at the same effort, especially in the heat. Pace by feel and power where you can, and treat heart rate as a check, not a target. We compare the options in power, heart rate, or feel.
• Aim for an even second half. If you are riding the last third at close to the pace of the first third, you paced it well.

Durability, the ability to hold good power deep into a long day, is what these events really test, and it is built by long rides and consistent, mostly easy training. How to train for a gran fondo covers the foundation. For ultra events, extend it: longer long rides, back-to-back days, and at least one ride into the night before the event.

Stops: the hidden clock

In a long event, your time off the bike adds up much faster than people expect. A ten-minute stop every hour is two hours over a twelve-hour ride. Stops matter, since you need to refill, eat, and sometimes rest, but each one should have a purpose.

Plan your main stops in advance, using shops, gas stations, and controls on the route. Know what you need at each: water, food for the next stretch, a proper meal, clothing changes for the night. Keep everything you need to reach on the move in an accessible place. And beware the comfortable chair. Long stops make your legs stiffen and your body cool down, and restarting gets harder every time.

Fueling for the whole day, and the night

The principles are the same as any long ride, but the duration changes how they play out.

• Eat early and keep going. Start in the first 20 to 30 minutes and eat every 20 to 30 minutes, day and night. At the steady, lower effort of ultra riding, around 60 grams of carbohydrate an hour is a sensible baseline, more if you have trained your stomach for it. How many carbs per hour explains the ranges, and train your gut explains how to raise yours.
• Plan for sweet fatigue. After several hours of gels and drinks, many riders cannot face anything sweet. Carry savory options, such as salted potatoes, sandwiches, pretzels, or rice cakes, and use shops for real food like soup, pizza, or a hot drink.
• Keep drinking, carefully. Drink regularly, add sodium in the heat, and do not force down more fluid than you need. Over-drinking is a real danger in very long events. See hydration and sodium.
• Handle a tired stomach. If nausea sets in, ease the pace a little, sip water, switch to plain or salty food, and build back up gradually. Stopping eating altogether usually makes things worse within a couple of hours.

In a 24-hour ride, the most important skill is not riding hard. It is still eating at 3 a.m.

Caffeine, the night, and your head

Caffeine is a powerful tool in ultra events, and its value is highest when you are most tired. Save it for when you need it: the late afternoon dip, the evening, and the hours before dawn when sleepiness peaks. Small, repeated doses work better than one large dose early on, which mostly wears off before the hardest part. Caffeine before a race covers doses and timing.

Riding through the night needs its own preparation. Test your lights on a full night ride before the event, carry warm layers, since temperatures drop sharply before dawn, and know that your mood will likely dip in the small hours. It passes, usually with food, daylight, or a hot drink. For events over 24 hours, a short nap of 15 to 20 minutes can do more for your safety and speed than pushing on while nodding off.

On safety: fatigue impairs judgment and reaction time. If you are drifting across the road, seeing things that are not there, or feeling unwell, stop somewhere safe and rest. Finishing late is always better than not finishing safely.

Train Fondo, a training and nutrition planning app for endurance athletes, plans the long-ride progression and the fueling for events like these from one model. It sets grams of carbohydrate per hour for every long ride, capped at what your gut has been trained to handle and raised gradually, sets fluid and sodium from your own sweat-rate test, and lets you plan caffeine on a timeline so you can see how much is on board at the hours that matter. For a race objective, its readiness view tracks your durability, long sessions, and fueling against what the event will demand.