I have watched more sportive riders blow up at the 70km mark than I can count. Almost every single time, the reason is the same. It is not fitness. It is not the bike. It is pacing.
What experienced riders know about sportive pacing: the rider who finishes strongest is almost never the rider who looked strongest at the start. The first 30 kilometres of any big sportive — the Etape, the Marmotte, Fred Whitton — are a graveyard of future blow-ups. Everyone feels brilliant. The adrenaline is flowing. And so you ride 10 to 15 watts above what you can sustain for the full distance. Those watts are not free. They come with an invoice that arrives around kilometre 80, and there is no negotiating the payment.
Why most sportive riders blow up
The physiology is not complicated. Your body stores roughly 1,600 to 2,000 calories of glycogen in the muscles and liver when fully loaded. At a steady endurance pace — 65 to 75 per cent of FTP — you burn a mix of fat and glycogen, and your stores last 3 to 4 hours with proper on-bike fuelling. Raise the intensity to 80 to 85 per cent of FTP and the fuel mix shifts dramatically. Glycogen burns at nearly double the rate. Your body cannot replace it fast enough, because gut absorption maxes out at roughly 60 to 90 grams of carbohydrate per hour.
Dr. Andrew Coggan's work on normalised power and intensity factor — the framework behind Training and Racing with a Power Meter — makes this visible. Every effort above threshold costs disproportionately more glycogen than the same duration below it. A 5-minute surge at 110 per cent of FTP on a climb does not cost the same as 5 minutes at 70 per cent on the flat. The NP calculation punishes those spikes.
The specific mistake most riders make is treating the first 30 kilometres like a different event. Riding at 82 per cent of FTP feels easy — for the first hour. But you are burning through glycogen at a rate your feeding plan cannot replace. By the time you feel the fatigue, you are already in debt. The legs go wooden, the power drops off a cliff, and the last 30 kilometres become a death march.
Here's the good news. This is fixable.
The negative split and why it works for sportives
Tim Kerrison built Team Sky's pacing philosophy around a simple principle: you cannot buy back what you spend in the first hour. The negative split — riding the second half of an event harder than the first — is not reserved for professionals. It is the most effective pacing strategy for any sportive rider with a power meter.
In practice, ride the first half 5 to 10 watts below your target normalised power, then lift to target or slightly above in the second half. On a 100km sportive where your target NP is 200 watts, that means sitting at 190 to 195 for the first 50 kilometres and then riding 200 to 210 for the back half.
Why ride slower when you feel best? Because the rider who holds back early is not actually tired in the second half — they just feel normal. Meanwhile, the riders who went out hard are crumbling. You are not riding faster because you found some hidden reserve. You are riding faster because you did not waste your reserves.
Dan Lorang, who coaches Primož Roglič, applies this same logic at the highest level. Watch Roglič in any Grand Tour mountain stage. He sits in, rides conservatively on the early climbs, and then attacks when everyone else has spent their matches. The amateur version is not attacking on the final climb — it is simply still having legs when everyone else is cooked.
Professor Stephen Seiler's research on intensity distribution reinforces this. The body performs best in sustained endurance events when the effort is steady and below the lactate threshold for the majority of the duration. Every spike above threshold depletes both glycogen and your capacity to recover from subsequent efforts.
Power-based pacing: the numbers that matter
If you have a power meter and you know your FTP, you have everything you need. If you do not know your FTP, get it tested or do a proper 20-minute field test before your event. Pacing by feel is guessing. Pacing by heart rate is delayed and unreliable. Pacing by power is precise.
For a 100km sportive lasting 3 to 4 hours, target an intensity factor of 0.75 to 0.80. If your FTP is 250 watts, your normalised power should be 188 to 200 watts. That is your ceiling, not your floor.
For a 160km century lasting 5 to 7 hours, drop the IF to 0.65 to 0.72. Same 250-watt rider — normalised power of 163 to 180 watts. I know that sounds low. It is supposed to. The riders who go out at 0.80 on a century feel incredible for 90 minutes and spend the last two hours questioning their life choices.
The TSS budget tells the same story. A well-paced 100km sportive costs 180 to 250 TSS. A 160km century, 250 to 350 TSS. If your event TSS exceeds 1.5 times your average weekly training load, you are in trouble in the final quarter regardless of pacing — your body is not conditioned to absorb that much stress.
Bradley Wiggins said something that stuck with me. He talked about learning to ride the climb rather than ride against his rivals. That is the mentality for a sportive. You are not racing anyone. You are riding a distance at an intensity your body can sustain.
How to pace the climbs without blowing up
Climbs are where most pacing plans fall apart. The road tilts up, the group surges, and suddenly you are riding at 95 per cent of FTP because everyone around you is pushing. Let them go.
For climbs under 10 minutes, cap your power at 85 to 90 per cent of FTP. A 250-watt rider should be climbing at 213 to 225 watts, not the 250 to 270 that the adrenaline and group pressure push toward.
For climbs longer than 15 minutes, drop that cap to 80 to 85 per cent of FTP. On a 20-minute climb at the Marmotte, the difference between 85 per cent and 95 per cent is not just a minute or two of time. It is 15 to 20 minutes of flat-road recovery afterwards where your power drops below what it should be. The time you gained on the climb, you give back on the valley section.
Before the event, I study the course profile and set a power ceiling for each climb based on its duration. Short, punchy climbs get a higher ceiling. Long, sustained climbs get a lower one. I write those numbers on a piece of tape on my top tube. When the climb starts, I look at the number, not the riders around me.
Feeding strategy is pacing strategy
Here is where even smart riders get it wrong. They build a pacing plan, set their power targets, and treat nutrition as a separate problem. It is not. Pacing and feeding are the same strategy. If one is right and the other is wrong, you still blow up.
Start eating from the first 20 minutes. I know you are not hungry. Eat anyway. Your gut absorbs carbohydrate best when intensity is moderate. The first hour is the cheapest hour to fuel — gut function is at its best, and the carbohydrate you take on board is available as fuel for hours 3 and 4.
The target is 60 to 90 grams of carbohydrate per hour. The only way to eat that much without stomach problems is to practise it in training and to keep your intensity in the zone where your gut can function. Ride too hard, and your gut shuts down because blood diverts to the working muscles. Your nutrition strategy becomes useless because you cannot absorb it.
I set a timer on my head unit to beep every 20 minutes. When it beeps, I eat something. A gel, a bite of bar, a swig of carb drink. Miss two or three of those windows in the first half and you are looking at a 40 to 60 gram deficit you cannot make up later.
Even 2 per cent dehydration — about 1.5 litres for a 75kg rider — reduces power output by 5 to 8 per cent. Drink to a plan, not to thirst.
Reading the course profile before race day
For any sportive over 100km, sit down the night before with the course profile and break the ride into thirds. First third: conservative, below target NP, eating consistently. Middle third: settling into target NP, managing the main climbs. Final third: this is where the negative split lives.
When you know the course, you know when to eat — on the flat before a climb, not during it. You know that the 3-kilometre ramp at kilometre 65 is the hardest effort of the day and you need to arrive with something in the tank. Without that knowledge, every tactical decision is reactive. You are guessing, and guessing costs watts.
I mark the feed stations on the profile, note which climbs I need to cap power on, and identify flat sections where I can eat without distraction. This takes 15 minutes the night before and it changes the entire ride.
Putting it all together on event day
Let me give you the practical version of all of this for a hilly 130km sportive — the kind of thing you might face at the Etape du Tour or the Fred Whitton.
First 40km: ride at 70 to 75 per cent of FTP, which will feel easy. It should feel easy. Eat from the first 20 minutes. Hit 60 to 80 grams of carb per hour. Stay hydrated. Let the fast starters go. This is not your race yet.
Middle 50km: settle into 75 to 80 per cent of FTP. This is your working zone. Cap climbs at the percentages I mentioned earlier. Keep eating on schedule. You should feel like you are working but comfortable. If you feel like you are suffering, you are going too hard. Drop 10 watts.
Final 40km: if you have paced and fuelled correctly, you should feel surprisingly good relative to the riders around you. This is where you lift to 80 per cent of FTP or slightly above on the flat sections. Maintain your feeding. This is the payoff for the discipline you showed in the first 40 kilometres.
That is the negative split in practice. Not a theory. Not something that only works for professionals. A real, repeatable strategy that I have used at the Etape, at the Marmotte, and that riders inside the Roadman community use every sportive season.
The mindset that makes this work
The hardest part of pacing is not physical. It is watching people ride away from you in the first hour and trusting that the plan works. That takes confidence, and confidence comes from having done the numbers.
If you know your FTP, you know what intensity factor you can sustain. If you know the course, you know where the demands fall. If you know your fuelling plan, you know you will not bonk. The three together — power targets, course knowledge, feeding plan — give you the confidence to ride your own ride.
And here is the best part. When you execute a properly paced sportive, the finishing kilometres are honestly enjoyable. You are not in survival mode. You are not counting down the minutes. You are riding your bike, feeling strong, passing people who went too hard two hours ago. That is a good day on the bike.
If you want to dig into this stuff with other riders who are training for the same events, come and join us inside the Roadman community at skool.com/roadmancycling. We talk pacing, power targets, course profiles, all of it — with people who are actually doing the sportives, not just reading about them.