Reading your numbers. The power-duration curve.

Your curve is your fingerprint.

So you understand CP and W prime. You know where the battery starts and stops. Now I want to show you how to actually read yourself as a rider.

Because that power-duration curve we just talked about? It's not just a line on a graph. It's a fingerprint. And if you know how to read it, it tells you exactly what kind of rider you are, where your strengths sit, where your weaknesses are, and, most importantly, where to spend your training time.

The problem is, most people never actually look at theirs. They know their FTP. Maybe they know their five-second power. But they've never sat down and gone "right, what does the shape of this thing tell me?"

That's what we're doing now.

Reading the curve.

The shape matters more than any single number. Two riders can have the same FTP but completely different curves. One might be explosive on the left side, big sprint, big five-second power, and drop off steeply. The other might be flat across the top, no big kick, but they hold power forever. Same FTP. Completely different riders. Completely different training needs.

Walk through the curve left to right: neuromuscular peak (pMax), anaerobic capacity (W prime), the threshold zone (CP), the endurance tail. Each part tells a different story.

Where your curve is steep, you're losing power fast. That's a weakness or at least a limiter. Where it's flat, you're holding power well. That's a strength.

The most common thing I see in time-constrained riders: strong in the middle (threshold work from turbo sessions), weak on the left (no sprint or neuromuscular work), and dropping off too fast on the right (not enough volume to build the endurance tail). That's a signature pattern and it tells me exactly what to prescribe.

Rider types.

There's a framework I use when I first look at a rider's data. Four types. And I want to be clear, these aren't boxes. Nobody is purely one thing. But they're useful as a starting point because they change how I think about training.

Now, I should say, there are more complex profiling systems out there. Some coaches use six types, some use eight, some build entirely individual models. I've tried most of them. And I keep coming back to four, because the whole point of a type is to give you a useful starting point, not to perfectly describe reality. The more types you add, the more you're pretending you know something you don't. Four is enough to change how you think about training. Anything beyond that, you're better off just looking at the actual data.

Sprinter. High neuromuscular power, big pMax, decent W prime. The curve is tall on the left and drops fast. These riders win on the kick. Training focus: they don't need more sprint, they need to get to the sprint with something left.

Puncheur. Strong across the one-to-five-minute range. The curve stays high longer before it drops. These are the riders who attack on short climbs, who can go hard repeatedly. Training focus: extending that ability deeper into rides, durability of repeated efforts.

Climber. High watts per kilo at threshold and above. The curve might not look impressive in raw watts, but relative to body weight it's shifted up. Training focus: depends entirely on the type of climbing they're doing. A ten-minute climb and a forty-minute climb are completely different problems.

All-rounder. No huge peak anywhere, but no big weakness either. The curve is relatively smooth. These riders are competitive everywhere and dominant nowhere. Training focus: find the thing that gives them an edge in their specific events and sharpen it.

Why profiles lie.

Now, I want to be honest about the limits of this. Because rider profiling is useful, but it can also be misleading.

Here's why. Take the same rider. Test them when they're fresh and rested, you get one profile. Test them at the end of a long training block, you might get a completely different one. The sprinter who can't sprint at hour four isn't really a sprinter when it counts. The climber whose watts per kilo drops 15% in the last hour of a stage isn't climbing at their profile anymore.

A power profile is a snapshot of capacity. It doesn't tell you about access, how much of that profile you can still reach when you're fatigued.

I've seen riders whose profile looks average when fresh but who barely lose anything when tired. Those riders win races. And I've seen riders with incredible profiles who fall apart after three hours. Those riders get dropped.

The real question isn't "what's your profile?" It's "what's your profile at hour four?" And that's where durability comes in, which is coming up in the next chapter.

Raw watts vs watts per kilo. Same rider can look like a sprinter in raw power and a climber in w/kg. Which one matters depends entirely on the terrain and the event. Profiles don't exist in a vacuum.

The 15% rule. If your threshold power divided by your five-minute power is less than 85%, your aerobic engine is lagging behind your top end. I call it the 15% rule because that's the maximum gap I want to see between your threshold and your five-minute power before the aerobic base is too weak to support serious intensity work. And I'll be straight about it. This is mine. It isn't from a paper. It's a coaching heuristic I've refined across hundreds of riders and it holds up. Some rules in coaching come from research. Others come from years of watching what works. This is the second kind, and I'd rather tell you that openly than dress it up as something it isn't.

What your data is actually telling you.

Your curve changes over time, and the direction of that change tells you whether your training is working. Curve shifting right (more endurance power) means aerobic development working. Curve shifting up at threshold means intensity working. Curve getting taller on the left means neuromuscular development.

Seasonal curve shifts. In base training, the right side of your curve should be building. During intensity blocks, the middle and left should come up. If neither is moving, something is wrong with the training stimulus, or you're too fatigued to express it.

Compare your curve to itself, not to other people. Your genetics, your age, your training history, your time availability, all of these set boundaries. The question is whether you're moving the curve in the direction that matters for your goals, not whether it looks like someone else's.

The fatigued curve. If you could overlay your fresh curve and your curve at four hours, the gap between them is your durability picture. Small gap means durable. Big gap means you're losing a lot to fatigue. We don't have a clean way to do this in most software yet, but the concept is what matters.

The map before the territory.

So that's your power-duration curve read like a coach, not like a data scientist. The shape tells you who you are. Your rider type gives you a starting point for where to train. And the limits of all of it, the fact that it's measured fresh, the fact that profiles change under fatigue, that's the thread we keep pulling on.

Because everything we've done so far is a map. It's useful. But the territory, the actual ride, the actual race, the moment where you're deep in and the numbers stop matching what they said on test day, that's where this playbook is really going.

Next up: why your training zones are probably wrong. And I mean that.