Everything I seem to read about FTP suggests it’s the theoretical and generally near unachievable for an hour.
Today I had an attempt at Sa Calobra and managed 235w over the 50 minutes.
My AI set FTP is currently 236. My question is, if I actually achieved my ftp and continued riding at Z2/3 for another 30 miles, is it likely that my ftp is set a bit low?
How does 236w feel in training? Some people can achieve it on the right day and everything goes right, especially when indoor via outdoors and to a degree the right gradient (its easier to hold a consistent power up a consistent hill) are taken into account. I exceeded mine (well for 57 mins and not 60mins) but thats a one off I wouldn’t want to up my FTP and burn out and not be able to get close to that again.
I would assume you’ve progressed and its time for an increase.
FTP is not 60min mean-maximal power.
I did 5x10min @ 235 the other day quite comfortably and that was in 30c, but that was outdoors.
I haven’t trained indoors for a while to be fair.
Its maybe time to bump it up a bit then, at least outdoors, but be a bit wary of bumping up too much (especially for indoors) and burning out but that less of an issue if you are riding purely outdoors at the moment. I’m no coach but I like things in 5 and 10s so for outside Id round the 236 to 240 w initially and see how you get on.
Really depends on your definition of FTP. I consider FTP to be synonymous with maximum steady state lactate. Opinions/definitions are all over the place, just do a quick search here and you’ll find days of debate. For me, MSSL is a useful number to use from a pacing standpoint and it’s also measurable and repeatable and isn’t as dependent on your motivation on a test day. Much more meaningful and repeatable than coming up with a number for 1 hour power. I may only be able to hold MSSL for 30 minutes when I’m not terribly fit and I might be able to hold it over an hour when really fit. If you are just using FTP in the context of setting training zones, FTP is somewhat arbitrary and doesn’t matter if it’s off a bit (particularly in the context of adaptive training and progression levels). However you define it, your ability to hold it for a given period of time varies greatly by person and level of fitness. For me, I need to be pretty fit and doing a bunch of volume to hold FTP (MSSL for me) for an hour. HR will will be creeping up and motivation has to be pretty high to push beyond ~45 minutes.
Seems like your FTP is pretty accurate to me, not knowing anything else about you. Being able to do FTP for 50 minutes and then ride endurance afterwards shouldn’t be an unusual thing. It’s a quality training session is what it is.
You’ve done something extremely rare: a post that strongly suggests your FTP is fairly accurate.
I can’t remember the last time that happened around here.
Good for you 
Read more! 
Completely baffled by the votes for saying your ftp value should be increased. If you can do 50 minutes at that number you’re probably pretty accurate. I wouldn’t change it
Well, you didn’t say how he felt during that 50 mins, so there isn’t really enough information to say if it should be raised or not. Being able to do z2 for 30 mins after the effort doesn’t really reflect on the ftp effort, as you should be able to recover after riding at ftp (i.e., it’s not usually a fall on the floor gasping for breath kind of effort).
If you said the 50 mins at 235 was easy, or that you started at 235 and ramped up to 250 over the 50 mins, then I’d say you’re probably due for an ftp bump.
He said 30 miles, so probably more like 90min+, but the point still stands.
To me, a warmup + 50 min at threshold (usually in interval form) + 90 min endurance is, again, a quality workout.
And his threshold probably isn’t higher than 235 IMO. It’s probably bang on.
You didn’t mention anything about your equipment.
Could be your power meter was reading high.
I guess I didn’t provide enough info about the ride.
The effort was 2.5 hours into my ride. Around 3000ft of elevation and 30 miles done at a mix of z2 and sweet spot depending on grade.
The effort was tough, by the end I had a headwind and emptied the tank for the last 3-5mins at 250-300w. I was cooked at the top, I’d have surveyed very hard or all out but I didn’t fall off the bike, I continued on to the next cafe!
Ride back was around 1000ft of elevation, a lot of down hill and flat.
But interesting take. I’d rather take it as my ftp being correct for sure.
With that additional information you provided and knowing Sa Calobra and roads to get there, I’d say you must have emptied the tank a little before you even started the effort. So your FTP is at least 236W, maybe a little more. You’re definitely close to your MLSS at that average power so that’s a pretty good and accurate value to anchor your training to (which is really the only actual use of the FTP number anyway). If you like round numbers it won’t hurt to bump it to 240 as that’s a rounding error anyway. Or leave it at 236 and keep on riding, it’s close enough for all intents and purposes.
Thanks for all the help, some great informatoin and I think I’m convinced that I should just leave my FTP where it is for the purposes of training.
I had an AI FTP update the other day and it actually dropped my FTP by 2 watts to 234. I’m guessing a month of very little structured training and a lot of big days on the bike followed by little breaks aren’t really conducive of an FTP increase.
Back to the plan next week
Depends on how ‘on/off’ that effort was - for me, as everyone’s definition will vary, its about consistent time at +/- % of your FTP number - again for me, this +/- % I consider to be pretty narrow.
