Why the Standard FTP Test Often Fails CrossFit Athletes
FTP is one of the most popular endurance markers out there. A lot of athletes know their number and can compare it across bodyweights using watts per kilo. That part is useful. If you want a broader look at endurance development in CrossFit, see the full guide on muscular endurance for CrossFit.
The original idea behind FTP
The true FTP test tries to find the power you can hold for a full hour. That is supposed to represent your anaerobic threshold. For some well-trained endurance athletes this works reasonably well. They can actually sustain that intensity close to an hour.
For most people who are less trained, the reality is different. You might hit your threshold but only hold it for 40 minutes before you fall off. The hour-long test is also extremely impractical. It requires perfect pacing and a lot of mental management.
The 20-minute shortcut and where it breaks
This is why the 20-minute test became the standard. The assumption is that you take 95% of your 20-minute power and that gives you a decent estimate of your one-hour power. For athletes with a relatively flat fatigue curve, this is often close enough.
CrossFit athletes are different. You are usually very good at holding high power for 20 minutes. After that point the drop-off is much steeper than for pure endurance athletes. Many people find that 90% or even 85% of their 20-minute number is more accurate for the hour mark.
Why the 20-minute test still has problems
Even the shorter test has issues. There is still a lot of strategizing and pacing involved. You have to decide exactly when to push and when to hold back to get the best score. That makes the result less clean than it looks on paper.
A step test is often more practical. It removes a lot of the pacing games. I use the step test and then take roughly 75% of the power at the end of the test as a starting point for writing training zones and progressions.
Key Takeaways
FTP can be useful for comparing athletes, but the standard testing methods are not always accurate for CrossFitters.
The 20-minute test assumes a linear fatigue curve that many CrossFit athletes do not have.
A step test with a 75% starting point is often more practical for building training progressions.
Want help testing your actual endurance markers and building training around them?
Frequently Asked Questions
Should I still do an FTP test if I do CrossFit?
You can, but treat the number as a rough starting point rather than gospel. Be ready to adjust the percentages based on how you actually feel in longer efforts.
Is the step test better than the 20-minute test for everyone?
It removes a lot of pacing strategy, which makes it more reliable for most people. The trade-off is that you still need to interpret the result and test how it feels in real training.
Can I use watts per kilo from an FTP test to compare myself to others?
Yes, but only as one data point. Durability, pacing ability, and how your power drops over time matter just as much in CrossFit.