Here’s my situation; began using TR at the end of September and started with a 242W FTP from the ramp test.
Went through SSB LV 1 in October and November and, following a break for a vacation and getting sick, did another ramp test at the beginning of December before starting SSB LV 2 - tested at 235W. A little disappointing but I think (in retrospective) that I was a little fatigued during that test and was coming off of being sick for 2 weeks - likely not the best testing scenario.
Fast forward to the past couple of weeks and the workouts are feeling really easy - I found myself turning up the intensity on Jepson, Gendarme +3, and English. They seemed too easy - heart rate not really coming up, just plowing through the intervals etc. (first world problems, I know…) So yesterday, I decide to redo the ramp test to see if, between the poor result last time and (hopefully) improvements since then, my FTP setting should just be higher. Result: 285W wow…
So, today I take that 285W into Mills +1 and get absolutely buried. I was barely able to get through the intervals with the intensity at 92% or 93% and failed at anything higher.
I’m thinking that I somehow(?) just dug too deep on the ramp test and that the 285W isn’t representative of my actual ability to do the work. So I think I need to reduce that, but I’m not sure by how much - perhaps split the difference between the old 235W and the more recent 285W and go to 260W? Perhaps take that 92% to 93% level of the 285W that I was able to work at and set it at 265W? Perhaps something else?
What devices are you using for power? It sounds like it could be a bunch of conflating factors given the sickness and the large change in number.
Here’s a thread that may be useful…
Thanks but that user’s issue and mine aren’t the same; I used the same bike, tire, trainer, garage, music, etc. for all of the efforts and made sure to do a spin down calibration before each of them.
It’s a Kurt Kinetic Road Machine Smart control.
Sorry for the odd formatting in my replies - it didn’t look like I was replying to the replies so I redid them and now it looks like I’m replying to myself…
Did you have the same tire pressure/warmup/calibration setup between the two tests?
I do. I only have 1 bike that will go on the trainer and I’ve only ever used 1 tire with it - a Continental Home Trainer tire. I also air up the tire to the same 95psi before each workout. The drum/tire interface pressure is a little tough to quantify (it’s just a knob you turn by hand) but I try to keep it roughly the same. My hope is that the spin down calibration takes care of this last variable.
There is a good post on the blog about what to do about odd tests and if you think FTP is set too high. Spoiler alert; retest or manually decrease to manageable number.
I would suggest you just retest and see if it was an oddball occurrence.
That seems like a pretty sane approach.
A question though; what if I’m able to (somehow) do really well on the ramp test but then cannot function on workouts crafted around that power level? Perhaps go to the 8 or 20 minute FTP test instead of the ramp test?
How fatigued where you going into the ramp test vs Mills +1? I had a situation a few years ago where I rested very well prior to the 20 minute FTP test and saw a nice jump in my FTP. But, I couldn’t manage the workouts. As a triathlete, I always seem a bit fatigued. I couldn’t do over-unders at my new glorious FTP the day after a hard swim or a hard run.
Great gains! 
I can’t imagine ever taking a big ftp boost straight into a VO2max fest! Why Mills let alone Mills +1?
I would take a day, then do something like Mount Field or Cumberland…
In my experience VO2max intervals need to be built towards, and with such a big jump in watts you’re just not used to that high an output over those interval periods yet.
I think you’ll get there in time 
I suppose I’d say I was more fresh than I usually am? I typically do TR workouts M, W, and F, lift weights T and Th, and go for an outdoor ride on Sat. morning. I did this ramp test on Tuesday morning after taking it relatively easy Sunday and Monday (had an awesome Sat. morning ride but then no workouts, just home improvement projects between it and the test.)
Try the 8 min test.
Mark the dial at the top when it’s at it’s proper setting. Then you’ll know where you need to tighten the knob to every time to be consistent.
TR does not suggest that. Keep your ramp test the same so you have comparable numbers. Are you following a plan or picking workouts? Maybe that was just the wrong workout at that time.
Well, there’s that. I didn’t think I was really that fatigued after the test and I’m always hearing about the coaches doing another workout afterwards so I figured the next day wouldn’t be too tough.
I’m following SSB LV 2 but I have to move things around sometimes to accommodate family, career, etc.
That’s a great idea - thanks.
THIS!!! 
I like VO2 sessions but I’ve learned my lesson!! I usually go with a SS or even an Endurance workout after a bump in FTP just to acclimatise the mind, body, and soul.