Staring at a 200km or 300km ride on paper can feel overwhelming. But what if you didn't think about it as one massive ride? Chunking is a strategy used by ultra-endurance cyclists to break a long ride into smaller, more manageable time blocks — typically 4 to 5 hours each. Instead of worrying about the whole day, you only need to think about the next chunk.

What Is Chunking?

Chunking is a technique borrowed from psychology — the idea that we handle complex tasks better when broken into smaller pieces. For cycling, it turns a daunting all-day effort into a series of focused sessions.

A chunk is typically a time-based block of 4 to 5 hours. Within each chunk, the rider plans three key elements: riding time (e.g., 4.5 hours of actual pedalling), rest time (e.g., 15–30 minutes for recovery and refuelling), and nutrition strategy (carbohydrate targets, hydration volumes, and specific foods).

The beauty of chunking is that it's not about distance — it's about time. A flat, fast 120km in 4 hours is one chunk. A mountainous, slow 80km in the same 4 hours is also one chunk. You're training your mind and body to focus on consistent effort over time, not arbitrary distance markers.

Planning Your Chunks

When planning what goes into each chunk, start with these considerations:

Riding time: How many hours of actual pedalling will you do in this chunk? Be realistic about your pace, terrain, and fitness level.

Rest stops: Plan for 3–15 minutes of rest depending on your needs. A quick snack stop might be 3 minutes; a meal break might be 20–30 minutes. Include these in your total chunk time.

Nutrition targets: Aim for 60–90g of carbohydrates per hour during the ride. For a 4.5-hour chunk, that's roughly 270–400g of carbs total. Mix sports nutrition (gels, chews, bars) with real food (sandwiches, rice cakes, bananas) for variety and satiety.

Hydration: Plan for 500–750ml of fluid per hour, adjusted for heat and humidity. A 4.5-hour chunk in cool conditions needs roughly 2–3 litres; in hot conditions, you might need 3–4 litres.

Tip: A simple formula: for each chunk, calculate your calories (roughly 200–300 per hour for endurance pace), your fluid needs, and any gear changes needed. Write it all down — don't rely on memory when you're tired.

The Chunk Bag

The practical magic of chunking is preparation. Before the ride, you prepare a bag (or container) for each chunk containing everything you need to execute that block:

• Food: Energy bars, gels, chews, sandwiches, rice cakes, fruit — whatever works for your stomach
• Drink: Pre-mixed bottles with electrolytes, or powder sachets ready to mix
• Spare kit: Arm warmers, gilet, rain jacket — gear for changing weather or temperature shifts
• Spares: Inner tube, CO2 cartridge, chain lubricant
• Personal items: Sun cream, lip balm, medication, blister treatment

When you finish one chunk and pull into your rest stop, you grab the next bag and you're ready to go. No faffing, no forgetting things. Each bag is self-contained, and the mental shift from "I just finished the first 4 hours, only 8 more to go..." to "I finished chunk 1, time to crack on with chunk 2" is surprisingly powerful.

Support Scenarios

How you set up your chunks depends on the type of support available during your ride.

Loop Routes

If your route loops back to a base (home, car park, hotel), you can leave chunk bags there. Ride out, come back, swap bags, head out again. This is common for audax-style training rides and events with a headquarters. It also means you can leave heavier items at base and only carry what you need for the current chunk.

Escort Vehicle

With a support car following or leapfrogging ahead, the driver holds your chunk bags and hands them over at pre-arranged points. The driver can also prepare hot food, refill bottles with cold water, and hold spare clothing. This is common in events like RAAM (Race Across America) and LEL (London–Edinburgh–London) where supported riders have crew.

Self-Supported

For bikepacking or unsupported audax rides, you carry your chunk supplies on the bike. The chunk bag concept still works — organise supplies in separate ziplock bags or stuff sacks, one per chunk. When one's finished, move to the next. It keeps things structured even without external help.

Drop Bags

Some events let you send bags ahead to checkpoints. Pack each drop bag as a chunk bag — everything you need for the next section. Label clearly with your name and the checkpoint number. A good rule of thumb from ultra-running applies here too: include a "Plan B" food option in each bag in case your stomach rebels against your primary choices.

A Worked Example

Here's how chunking might look for a 300km audax in 15 hours:

Chunk 1 (0–75km, ~4.5 hours): 3 bottles, 4 gels, 2 flapjacks, 1 banana, arm warmers (early morning start — you'll need them).

Chunk 2 (75–150km, ~4.5 hours): 3 bottles, 4 gels, 2 sandwiches, electrolyte tabs. Drop the arm warmers — it's warmed up now.

Chunk 3 (150–225km, ~4 hours): 3 bottles, 4 gels, 1 sandwich, energy chews. Add a gilet (afternoon cooling kicks in around the 200km mark).

Chunk 4 (225–300km, ~3 hours): 2 bottles, 3 gels, caffeine tabs (you'll need the boost), front light plus spare battery (if finishing in the dark).

Total across all chunks: 11 bottles, 15 gels, 3 sandwiches, 2 flapjacks, 1 banana, electrolyte tabs, caffeine tabs, arm warmers, gilet, light, batteries.

Notice how each chunk is different? Early on you're adding layers; later you're adding caffeine and lights. You're also adjusting food type — sandwiches in the middle when you have time to eat, quick gels towards the end when you just want to keep moving. This is smart chunking: each chunk is tailored to where you are in the ride.

How PitStopper Helps

Chunking becomes even more powerful when combined with route planning tools:

• Identify refill points: Use PitStopper to find water taps, cafes, and shops within each chunk of your route. This tells you where you can top up without getting caught short.
• Clock time features: PitStopper's clock time feature shows when you'll arrive at each point — useful for knowing if shops will be open or if there's shade for a break.
• Export waypoints: Export your route with chunk boundaries marked as waypoints to your GPS device. You'll get alerts when each chunk is coming to an end, keeping you mentally on track.
• Split your route: Use PitStopper's split route feature to match your chunks, giving you distance and elevation stats for each segment. If chunk 3 has 1,000m of climbing, you might need more time or fuel.

Tip: Before your event, load your GPX route into PitStopper and add custom waypoints at each chunk boundary. Include the anticipated arrival time in the waypoint name (e.g., "Chunk 2 — 2:30pm"). When you export to your GPS, you'll have a clear timeline for the entire event.

Tips for Getting Started

1. Start with your total ride time and divide into roughly equal chunks. A 12-hour ride becomes three 4-hour chunks. A 15-hour ride becomes three 5-hour chunks.
2. Plan nutrition per chunk first. This is the most important element. Get carbs and hydration right, and everything else falls into place.
3. Pack each chunk bag the night before. Label them clearly (Chunk 1, Chunk 2, etc.) so there's no confusion during the ride when you're tired.
4. Practice on training rides. Test your chunk duration and nutrition plan before race day. A 300km audax is not the time to discover your stomach can't handle those particular gels.
5. Be flexible. If you're ahead or behind schedule, adjust the remaining chunks. Chunking is a framework, not a prison.
6. Include a bail-out plan. Know where you can cut the route short if needed — a train station, a taxi rank, a place to stay overnight. Ultra-distance cycling can take turns; have an exit strategy.

Conclusion

Chunking won't make the kilometres disappear, but it turns an intimidating distance into a series of achievable sessions. When you're 180km into a 300km ride and feeling the fatigue, knowing you only have to focus on the next 4 hours — and that everything you need is already packed and ready — makes all the difference.

The strategy transforms ultra-distance cycling from a vague, exhausting ordeal into a series of manageable challenges. Each chunk is a separate puzzle to solve. And once you've solved a few, you realise you can solve many more.