Every cyclist gets to the same question eventually. You have ridden fifty miles. You have ridden seventy. You have come home from a long Saturday and thought: could I have kept going? Could I have done a hundred?
The New Forest 100 is the best place in Britain to answer that question. One hundred miles through ancient woodland, open heathland, wild ponies standing in the road, and the quiet lanes of Hampshire — with barely 1,200 metres of climbing across the entire route. No Alpine passes. No Welsh ramps. No 15% walls that force you off the bike. Just 161 kilometres of gentle, rolling terrain that asks one thing of you: can you keep pedalling?
Here is the thing nobody tells you about your first century. The fitness required is lower than you think. The nutrition required is higher than you think. And the mental challenge of miles 65 to 85 — the stretch where the novelty has worn off and the finish is still an hour away — is something no training ride fully prepares you for. This guide covers all three.
Key Takeaways
- The New Forest 100 covers approximately 100 miles with only 1,100-1,300m of climbing — making distance, not climbing, the sole variable you are training for
- Target 2.0-2.3 W/kg for a comfortable finish at 25-28km/h average — this event rewards sustainable aerobic power and fuelling discipline over raw fitness
- A 12-week build peaking at 8-10 hours per week with progressive long rides from 3 hours to 5-6 hours is sufficient preparation for a first century
- Fuelling is where first-century riders fail — the wall at mile 70 is not a fitness problem, it is a nutrition problem, and it is entirely preventable with a structured eating plan from mile one
- New Forest ponies, cattle, and pigs wander freely on the roads — expect to slow or stop for animals, and never assume they will move out of your way
- The event offers shorter route options at approximately 50km and 100km — choosing the right route for your fitness is smarter than choosing the longest route for your ego
- September conditions in Hampshire are typically mild but rain is always possible — a packable gilet and the ability to ride comfortably in light rain are essential preparations
Course Profile and Key Sections
The New Forest 100 is not a course that demands section-by-section tactical analysis. There is no climb to save energy for, no descent to recover on, no technical section that rewards bike-handling skill. The terrain is almost uniformly gentle. But the ride does have a shape — and understanding that shape helps you manage the day.
The Opening Miles: Forest Roads and Finding Your Rhythm (Miles 0-20)
The start from Brockenhurst rolls you straight into the forest. Canopy roads, dappled light, the smell of wet bracken if it has rained overnight. The first twenty miles are flat to gently undulating on decent tarmac through the heart of the national park. Groups form naturally and the pace settles.
This is where you set the tone for the whole day. What most people do: get swept up in the excitement, sit on someone's wheel who is averaging 30km/h, and burn through glycogen they will desperately need at mile 75. What actually works: find a group moving at 23-26km/h, settle into conversation pace, eat your first gel within the first 30 minutes, and accept that the riders pulling away now are either fitter than you or making a mistake they will pay for later.
One genuine hazard: New Forest ponies wander on the roads with complete indifference to cyclists. Cattle too, and occasionally pigs. You will need to stop for animals at some point. Never assume they will move.
The Eastern Loop: Heathland and Quiet Lanes (Miles 20-45)
The route opens up through the eastern reaches of the forest — heathland sections where the road straightens and the views stretch. Nothing exceeds 3-4% for more than a few hundred metres. Road surfaces vary between smooth Hampshire lanes and rougher forest roads with gravel patches at the edges.
By mile 30, the event settles into its true character. The groups have sorted themselves. The scenery is truly beautiful. This stretch is where you build confidence — everything is working, the pace is comfortable, you are eating and drinking on schedule. Enjoy it.
The Coastal Section and Southern Loops (Miles 45-65)
As the route sweeps south towards Lymington and the Solent coast, you pick up a sea breeze. On a calm day, barely noticeable. On a breezy day, a steady headwind across exposed coastal sections that costs more effort than any gradient on the course. The scenery compensates — salt marshes, boats on the Solent, the Isle of Wight across the water.
Let me break this down: you are at roughly the halfway point. You have ridden further than most of your training rides. The legs feel fine. The lungs are fine. The saddle is starting to make its presence known. This is normal. Eat. Drink. Shift your position every twenty minutes. Keep the conversation going.
The Middle Miles: Where Distance Starts to Tell (Miles 65-80)
Here is where it gets really interesting — and by interesting, I mean hard in a way that has nothing to do with gradient. The course threads back through the forest interior. Same gentle rolls as the opening miles. But you have been riding for four hours and your brain is starting to do arithmetic. Fifteen miles does not sound like much until you have already done sixty-five.
The wall, if it comes, comes here. Not because the course gets harder. Because the fuel runs out. A rider who has been eating 60-80g of carbohydrate per hour from mile one arrives at mile 70 feeling tired but functional. A rider who ate a banana at the first feed station and nothing else arrives at mile 70 feeling like the bike weighs twice as much. The difference between those two riders is not fitness. It is breakfast, lunch, and twenty gels.
The Final Twenty: When You Know (Miles 80-100)
Twenty miles to go. You have done it before in training. You have done it a hundred times on a Saturday morning. The difference is that this twenty comes after eighty. Your legs are heavy but they are turning. And somewhere around mile 85, a quiet thought arrives: I am going to finish this.
The final miles back into Brockenhurst carry a satisfaction that only comes from the first time. No mountain-top finish, no sprint for the line. Just the gradual certainty that you answered the question. The medal is nice. The knowledge is better.
Fitness Benchmarks
The New Forest 100 has a lower fitness floor than any mountain sportive. The absence of sustained climbing means the event is accessible to a wide range of riders — but you still need a baseline of aerobic fitness to cover the distance comfortably.
| Capacity | W/kg | Avg Speed | Ride Time | Experience | |---|---|---|---|---| | Strong finish | 2.5+ | 28-32 km/h | 5-5.5 hrs | Experienced, well-paced | | Comfortable finish | 2.0-2.5 | 25-28 km/h | 6-7 hrs | Trained, well-fuelled | | Completion | 1.5-2.0 | 20-24 km/h | 7-8.5 hrs | Minimum preparation |
Set your power targets with the FTP zone calculator and estimate your calorie burn with the calories calculator. For a 75kg rider at 2.0 W/kg, the New Forest 100 burns roughly 3,500-4,000 calories. That number matters more for your fuelling plan than your training plan.
12-Week Training Plan Overview
This plan assumes you are currently riding 3-5 hours per week and can ride 40-50 miles comfortably. If your longest ride is under 30 miles, allow 16 weeks instead and spend the first four simply building saddle time.
Phase 1: Base Building (Weeks 1-4)
Volume: 5-7 hours per week across 3-4 rides.
Eighty per cent of your riding at Zone 2 — conversational pace, nose-breathing effort. The goal is aerobic base, saddle time, and establishing the long-ride habit.
Anchor session: One long ride per week, building from 2.5 hours (week 1) to 3.5 hours (week 4). Flat to gently rolling terrain. Practise eating and drinking on the bike from ride one — this is training your gut as much as your legs.
Midweek: One easy 60-90 minute ride. One moderate ride of 75-90 minutes with 2x15 minutes at a tempo you could sustain for an hour — not hard, just purposeful. These sessions build the aerobic engine without generating fatigue that bleeds into your long ride.
Off the bike: Two sessions per week of core stability — 20 minutes each. Planks (3x45 seconds), side planks (3x30 seconds each side), dead bugs (3x10 each side), single-leg glute bridges (3x12 each side), and hip mobility work. A strong core holds your position on the bike for six hours. A weak one collapses at hour four and turns the final thirty miles into a lower-back survival exercise.
Phase 2: Distance Extension (Weeks 5-8)
Volume: 7-9 hours per week.
The long ride is the centrepiece now. Everything else supports it.
Long ride: Building from 3.5 hours (week 5) to 4.5-5 hours (week 8). By the end of this phase, you should have ridden 70-80 miles in a single outing. Full fuelling rehearsal on every long ride — eat what you will eat on event day, drink what you will drink. If a gel makes your stomach cramp at hour three, you need to know that now, not at mile 60.
Quality session: One per week. Sustained tempo — 2x20 minutes at 80-85% FTP with 5 minutes easy between. This is precisely the effort you will hold for most of the New Forest 100. Steady, sustainable, slightly-above-comfortable power you could maintain for hours. No power meter? Ride at a pace where conversation is possible but requires effort. The FTP zone calculator sets the exact targets.
Easy rides: Two midweek spins of 45-75 minutes. Recovery pace. These keep the legs moving without accumulating fatigue.
Core: Maintain twice weekly. Same movements, same duration. Add single-leg balance work — 60 seconds each leg, eyes closed. Proprioception matters when you are fatigued and your bike handling gets sloppy.
Phase 3: Century Readiness (Weeks 9-10)
Volume: 8-10 hours per week.
The big ride (week 9 or 10): 80-90 miles. Full dress rehearsal — the kit you will wear, the food you will eat, the bottles you will carry. Event pace, not faster. If you finish tired but functional, you are ready. If you finish destroyed, your pacing or fuelling needs adjustment and you have two weeks to fix it.
Quality session: 2x25 minutes at 80-88% FTP. Same sustained tempo work, slightly longer blocks. One session of 6x3 minutes at 90-95% FTP with 3 minutes easy between — this builds a small reserve of headroom above your event pace so the New Forest 100 never requires everything you have.
Volume management: If the big ride leaves you flat, cut the following week's midweek rides to 30-45 minutes easy. Absorb the training load before adding more.
Phase 4: Taper (Weeks 11-12)
Volume drops 30-40%. The fitness is in. You cannot meaningfully gain fitness in two weeks. You can arrive at the start line fresh or fatigued — and freshness is worth more than any interval session.
Week 11: 6-7 hours. Long ride of 2.5-3 hours at easy pace. One short session with 4x3 minutes at 90% FTP — openers, not builders. Two easy spins.
Week 12 (event week): Three short rides. Monday or Tuesday: 45 minutes easy with 3x2-minute efforts at tempo. Thursday: 30 minutes easy with 3x30-second accelerations. Friday: rest. Saturday: rest or a 20-minute spin. Sunday: event day. Arrive with fresh legs.
Key Sessions
The Progressive Long Ride
The most important session in the entire plan. Build from 2.5 hours to 5-6 hours over twelve weeks. Every long ride includes full fuelling practice — 60-80g of carbohydrate per hour, 500-750ml of fluid per hour. The physical training and the nutritional training happen simultaneously. By event day, eating on the bike should feel automatic.
Sustained Zone 2 Tempo
2x20-25 minutes at 80-85% FTP embedded in a 90-minute ride. This is the pace of the New Forest 100. Not hard. Not easy. Just honest, sustainable effort that you could hold for the whole day if you fuel it properly. Build the blocks from 2x15 minutes in week 3 to 2x25 minutes by week 9.
One Quality Session Per Week
The specifics vary by phase — gentle tempo in the base, longer tempo blocks in the build, and 6x3 minutes at 90-95% FTP in the peak to build a reserve above event pace. One quality session per week is enough. Two is unnecessary for a flat century. Three will leave you fatigued for your long ride, which is the session that actually builds century fitness.
Nutrition Strategy: Where First Centuries Are Won and Lost
Let me be direct about this. The wall at mile 70 is not a fitness problem. It is a nutrition problem. And it is entirely fixable.
Your body stores roughly 90-120 minutes of glycogen at moderate cycling intensity. The New Forest 100 takes 6-8 hours. The arithmetic is simple: if you do not eat, you run out of fuel at roughly hour two. The remaining four to six hours are a progressively miserable exercise in burning fat at a fraction of the power output your muscles are capable of. That is the wall. It is not mysterious. It is not about mental toughness. It is about glucose.
The good news: it is completely preventable. Use the fuel planner to calculate your exact requirements based on your weight and target pace.
Hour 1: Start eating within the first 20-30 minutes. One gel or half a bar plus 500ml of electrolyte drink. You will not feel hungry. Eat anyway.
Hours 2-3: 60-80g of carbohydrate per hour. Two gels, or one gel and one bar, or whatever your gut tolerates. Use the feed stations to top up bottles and grab a banana.
Hours 4-5: Same intake. Most first-century riders stop eating here because their stomach feels full or slightly nauseous. Both sensations are normal. Keep eating in smaller, more frequent amounts — half a gel every 15 minutes rather than a full gel every 30.
Hours 5-7: If you have fuelled properly, you still have energy. If you have not, the deficit is very hard to close. A caffeinated gel at mile 75-80 provides a genuine lift — 3mg of caffeine per kilogram of body weight peaks after 20-30 minutes and carries you home.
The day before: 8-10g of carbohydrate per kilogram of bodyweight spread across the whole day. Pasta, rice, bread, potatoes. Familiar food. Normal hydration.
Race morning: Breakfast 3 hours before the start. Porridge, toast with honey, a banana, coffee. 100-150g of carbohydrate. Nothing new. Nothing experimental.
Run your numbers through the hydration calculator as well — September in Hampshire can be surprisingly warm and dehydration compounds the fuelling problem.
Equipment and Gear
The New Forest 100 does not demand specialist equipment. If your bike is in good working order, it is good enough. Here is what actually matters.
Saddle comfort. If your longest ride is currently 3 hours, you have not tested your saddle for 6-7 hours. Do that in training, not on event day. Chamois cream is not optional for a century.
Tyres. 25-28mm at the correct pressure for your weight. Some forest road sections have rough patches and gravel at the edges — 23mm tyres pumped to 110 psi are less comfortable and not faster.
Spares. Two tubes, tyre levers, a CO2 inflator or mini pump, a multi-tool. Know how to change a tube before event day.
Clothing for September. Hampshire in September ranges from 12 to 20 degrees. Arm warmers and a gilet if the morning is cool — both pack into a back pocket. A lightweight rain cape if rain is forecast. Getting cold and wet at mile 60 with forty miles remaining is a miserable way to spend a Sunday.
Bottles. Two cages, two full bottles. The feed stations are well-placed but carrying enough between them removes the pressure to stop at exactly the right moment.
Race Day Pacing
The simplest pacing strategy for a first century: conversation pace for the first sixty miles, then ride the last forty however you feel.
Miles 0-30: 60-70% FTP. Conversation pace. Settle into a group. Eat. Drink. Enjoy the forest. If someone pulls away, let them go.
Miles 30-60: 65-75% FTP. You should feel like you are working but not hard. The effort is purposeful, not punishing. Keep fuelling to schedule.
Miles 60-80: 70-80% FTP if the legs allow it. This is where disciplined pacing pays off. The riders who started too fast are slowing down. You are not.
Miles 80-100: Whatever you have left. If you have paced and fuelled correctly, you will be surprised how much that is. The final twenty miles of a well-paced century feel better than miles 60-80 because the finish pulls you forward.
Common Mistakes
1. Starting too fast. The biggest error in every first century. The opening miles feel easy. The group is rolling. You feel strong. By mile 60, you are paying for the extra 2km/h you did not need in the first hour. Start slower than feels necessary. You will thank yourself later.
2. Underfuelling. Covered extensively above because it is precisely the mistake that ruins the most first centuries. Eat from mile one. Eat when you are not hungry. Eat more than feels natural. The wall is a nutrition problem, not a fitness problem.
3. Not testing saddle comfort. Your saddle is fine for three hours. Is it fine for seven? You need to answer that question in training. Saddle sores, numbness, and chafing that are manageable at mile 40 become serious problems at mile 80. If your saddle does not work for long distances, fix it before event day.
4. Ignoring the weather forecast. September in Hampshire is usually mild. Usually. Check the forecast 48 hours before and pack accordingly. Being cold costs watts. Being wet costs morale. Being both costs the ride.
5. Choosing the wrong route distance. The event offers 50km, 100km, and 100-mile options. If your longest training ride is 50 miles, the 100-mile route is a gamble. The 100km route gives you the full New Forest experience without the risk of mile 75 turning into a survival march. Choosing the right distance is smarter than choosing the longest distance. There is always next year.
Travel and Logistics
Getting there. Brockenhurst is 90 minutes by train from London Waterloo, or by car via the M3 and M27. Book accommodation early — September is peak season and 3,000-5,000 riders filling a small Hampshire village strips availability fast. Lymington and Lyndhurst are nearby alternatives if Brockenhurst is full.
Parking. Follow the event organiser's instructions and arrive early. Registration, kit check, and a warm-up spin all take longer than you expect.
The ponies. Not a quirky detail — a genuine safety consideration. Ponies, cattle, donkeys, and pigs roam freely. They stand on roads, cross roads, and do not respond to bells or shouts. Slow down, give them space, pass carefully.
Entry. Approximately £40-55 depending on when you register. Early-bird entries are cheaper and the event typically sells out.
Recovery Plan
Your first century deserves a proper recovery.
Immediately after: Eat within 30 minutes — 1-1.5g of carbohydrate per kilogram of bodyweight plus 20-30g of protein. Drink until your urine is pale.
Day 1 after: Complete rest or a 20-minute walk. Your legs will be stiff. Normal.
Days 2-3: Easy 30-45 minute spin if you feel like it. Zone 1 only. Active recovery, not training.
Days 4-7: Gradually return to normal riding. If you still feel flat at day 5, take another rest day. A century takes more out of a first-timer than an experienced rider.
What Comes Next
You have ridden a hundred miles. The question is answered. And almost immediately, a new question arrives: what now?
The RideLondon guide covers the UK's biggest closed-road century. The UK sportives guide maps out every major event in the calendar. And if the hills are calling, the 100-mile nutrition guide covers fuelling for harder events where climbing changes the energy equation.
Inside the Not Done Yet community on Skool, riders share their century stories, training structures, and the specific sessions that got them to the start line ready. If you are twelve weeks out from your first hundred miles and want a group of people who have been exactly where you are — that is the room.
The New Forest 100 is not the hardest sportive on the calendar. It is not the longest, the steepest, or the most dramatic. It is something better than all of those things. It is the one that proves you can.