When to take a FTP test?

My last FTP test was in December - Zwift rated me at 160W using the short test.

Last night I rode with a group - NP 178W for 94 minutes.

I thought FTP was supposed to be the best you could do for an hour. Does my ride last night mean it’s time to retest?

It means that you trained well the last 5 months and your new FTP will probably be north of 200W.
It also means that training load (and Fitness accordingly) for the last weeks is overestimated if you have training load based on power.
You could take the 1 hour best power from that ride as a good indicator if you went (almost) full out. If you feel like you could have done even more, do a new test and ride at least 20-30min, even better a full hour max (pace it evenly based on last nights result?). Make sure to push to your limit at the end.
Intervals should give you a new eFTP result based on that.
If you don’t like that kind of effort, do a FTP ramp test.

I know we had this conversation in another thread but I am still really stressed at these higher power levels - avg heart rate was 151bpm last night and 157bpm on Saturday 171W over 2h45m

so yah I agree the 160 is too low but I am definitely emptying the tank on these rides.

the trouble now is finding a day when I can take the test that will still leave me with enough energy to do these other rides. Between last night and Saturday I definitely need a couple days of recovery spin-only rides.

edit : I greatly prefer the short ramp tests - may not be as accurate but honestly if I can just get into the right 20W “bucket” that’s enough for me.

What´s the 1hr power for the yesterday ride?
It probably gives you a good enough estimate.

where do I see that?

still learning to use the tools.

On the activity Power Page, define the durations for Best Efforts as you wish and the table will then show your best Power output for those durations.
You could take 95% of a 20min effort or 100% of a 1hour effort, whichever is higher. That will get you close enough for your goals.

If you did a lot of sprints in that group ride, you might not be able to sustain 178W continuously. The normalized power formula weights efforts above FTP very heavily. That said, I agree with everyone else that you might want to try a test.

FTP is not the best you can do for an hour. As we exercise, our blood lactate levels rise. Below a certain power, our body can keep clearing lactate (it’s part of the aerobic fuel cycle), and it remains in equilibrium. Above that threshold, we’re out of equilibrium and lactate concentrations increase.

A 60 min all-out effort is an estimate of your FTP. It turns out that later work showed that people can typically hold their FTP for 40-70 minutes. The 20-min test is another estimate of your FTP, same as the ramp test. I would just do one of the tests, and then see how well you can hold the suggested FTP in intervals.

does this make any sense?

Is Normalized Power the wrong figure to look at? That’s what I was quoting at the top.

This would say I’m still at 160? Am I reading this right?

edit : this is my Sat ride



edit : this is assuming an FTP of 180 which I may need to go back and change back to 160 now

It all depends on what type of ride it was. Did you do sustained efforts at a relatively high and stable output? Or was it a chain of short high intensity bursts, with easy pedalling in between?
And what is Intervals estimating as eFTP for that ride (top right on the activity summary)?
What is Intervals estimating from your PDC curve? Overall Power page with the power/duration plot.

All these are different ways of estimating your FTP and give you a rough idea.

mostly sustained - see my comment above to the other reply.

If you hate testing (like most people) use eFTP it is unbelievably accurate if you’ve done an all out effort during a group ride/race.

every ride feels liek an all out effort right now lol