---
title: "Your FTP has nothing to do with how durable you are."
date: 2026-03-22
categories: ["Durability","Training"]
url: https://www.semiprocycling.com/digest/your-ftp-has-nothing-to-do-with-how-durable-you-are
author: Damian Ruse (SEMIPRO Cycling)
---
# Your FTP has nothing to do with how durable you are.

![](https://www.semiprocycling.com/digest/images/c237310370c8f447923093d6.webp)

## That is not an opinion. It is a finding from a 2025 study published in BMC Sports Science, Medicine and Rehabilitation.

Researchers took 20 well-trained amateur cyclists and tested them twice. The first time, fresh: a 5-minute and a 20-minute all-out effort. The second time, fatigued: same efforts, but only after completing 1,000 kilojoules of work at 80% of their fresh 20-minute power.

The drop in performance under fatigue? Around 10% on average across both tests. But here is the part that should change how you think about your training: there was no significant correlation between a rider's FTP or VO2max and how well they held up under fatigue.

The riders with the biggest engines did not automatically last the longest. Durability was its own thing.

**Three takeaways:**

1. **FTP and durability are not the same quality.** A rider with a 300-watt threshold can fade harder and faster than a rider sitting at 260 if the second rider has better fatigue resistance. Your fresh number does not predict your fatigued number.
2. **A 10% power drop changes everything.** If your 20-minute power is 280 watts fresh but drops to 252 after three hours of riding, that is no longer the same race. Your ability to close gaps, hold wheels, and respond to surges shrinks with every kilojoule spent. The riders who performed best under fatigue in this study were not necessarily the ones with the highest fresh power.
3. **Durability needs to be trained deliberately.** Because it is independent of the usual markers, you cannot assume that improving your FTP will improve your durability. They are separate qualities. If you only ever test and train fresh, you are only seeing half the picture.

## What to do with this

**If you race or do hard group rides:** Start paying attention to what happens after 90 minutes, not just what you can do in the first hour. Add quality efforts late in longer rides. Not junk miles, but purposeful work when you are already carrying fatigue. That is where durability gets built.

**If you train big hours:** Volume alone does not guarantee durability. What matters is whether you are including meaningful intensity after accumulated work. A four-hour ride with a hard 20-minute block at the three-hour mark tells you more about your race fitness than any fresh test.

**If you are time-capped:** You can still build durability with shorter sessions that simulate fatigue. A 90-minute session with 45 minutes of steady tempo followed by threshold or VO2max intervals is a durability stimulus. You do not need five-hour rides to train this quality, but you do need to stop resting before every hard effort.

**Bottom line: If you are only measuring what you can do when fresh, you are measuring the wrong thing. The race does not care about your best. It cares about your worst.**

*Reference: Durability as an independent parameter of endurance performance in cycling. BMC Sports Science, Medicine and Rehabilitation, 2025.*

## On my mind: Match the feeling

I had a call with a new athlete this week.

We were going through his data, his history, what he has been doing, and what he wants to get out of coaching. Normal stuff. But something clicked during the conversation that I have been thinking about since.

He already knew what good riding felt like. He could describe it. He could tell me what it felt like when a session went well, when the legs were there, when he was riding within himself and still going fast. He had the feeling.

What he did not have was confirmation. He did not know whether the data backed up what his body was telling him. He was not sure if the sessions that felt good were actually doing what he thought they were doing.

And that is when it landed for me, maybe more clearly than it has before. My job is not to hand someone a bunch of numbers and tell them what to feel. My job is to match the data to the feeling.

If a rider already knows what "good" feels like, then the coaching is about reinforcing that. Finding it in the power file. Showing them where it shows up in the numbers. Giving them confidence that what they felt was real, and that the work is going where it should.

That is a very different job to prescribing a set of intervals and hoping for the best.

Some athletes need to be taught what to feel. Some need to be shown that what they already feel is right. And the best coaching does not start with the training plan. It starts with understanding which one you are sitting across from.

I think this is also why durability matters so much as a concept. You can feel yourself fading in a race. You know the legs are going. But most cyclists have never connected that feeling to anything measurable. They just call it a bad day. Coaching is about helping someone see that it is not random. It is a pattern. And patterns can be changed.

Damian