Basically, I’ve had a drop of 60 w in FTP over the course of six weeks. Context: I trained fairly consistently over the summer for a 650 km audax that I did in early September. After the audax I took some time off cycling, had some work commitments during which time I did only a few rides, and then in early October I moved to a different town for a 3-month fellowship. The riding here is great, but really hilly. My last FTP test in late August came out at 233 w. I just started training consistently again (on a polarised plan) and my most recent test came out at 174 w. Yikes. That’s the lowest I’ve ever recorded. I don’t think the test was ‘wrong’ either because I’ve found the TR workouts since then appropriately challenging. Initially I thought it’s just because I was fatigued from starting training again and from all the hills here, but my legs have settled down. My RHR has been unusually high, but I don’t feel stressed (the fellowship is a nice gig) and I don’t feel sick. So what’s going on here?
maybe stupid to ask… but did you recalibrate your trainer after you moved?
What testing protocol are you using, the Ramp test with ERG ? Ramp tests are fine for 85% of the population and have the benefit of introducing relatively little TSS into your program (you should be able to test one day and workout at that level again the next etc). However, for 7.5% of the population they underestimate. They seem to for me and I think ERG also restricts me. I get far better results from a 20min tests, even a badly mispaced one will exceed the ramp result for me and if I get the pacing right a 20min test will far outperform a ramp test for me. Beside the difficulty pacing element though, the major drawback of the 20mins test for me is it does introduce excess TSS into your calendar.
Yes, I’ve been doing ramp tests, but I’ve been doing them throughout. So I did a ramp test in late August (resulting in 234) and one last week (resulting in 174). That should be comparable, surely?
Yes, I did. Both the power meter and the trainer. I had one dud workout when neither was speaking to the computer properly, but since then it’s been fine.
So whats your time away from training? 4-6 weeks? I broke my collarbone start of July, missed 10 days of training then 2 weeks of endurance before getting back on a plan and went from 220 down to 186. I’m only back up to 210 now, training consistently. 
Yes, around 5 weeks. In that time I went on two rides and had one indoor session, so really not much. But is that long enough to get totally deconditioned? I mean, my first FTP test ever came out at 211 I think.
On the same equipment?
I wasn’t expecting to lose 15% in a few weeks either…but I did!
Your detraining sounds plausible.
You lose different parts of your fitness at different rates. Blood plasma volume, for example, quickly takes a hit but also quickly comes back. You’ll probably gain a good percentage of your old fitness in just 2-3 weeks. And, the rest will come back much faster than it took to earn it the first time around.
Fitness can also be maintained on little volume which is why 20-30 minute trainer rides can be very effective.
Yes… though with the power measured on the turbo not with the power meter, and I know there are differences there
You took 5 weeks off and also had other life stresses….and it sounds like you tested fairly soon after you resumed training.
Sounds perfectly reasonable for FTP to drop that much. Don’t sweat it and just start logging the miles again…it will bounce back quick enough.
The short answer is that there are a ton a reasons this might happen, and the best response - I found - is not to worry and simply test again in two weeks or whenever you feel like it.
What were the results and dates of the past four tests?
I took about a month off of doing any efforts, but still continued to ride (with only about 1 week of nothing) after my car accident. I dropped about 30-40 watts.
But I did recover about 3-5 watts a week for several weeks after, so I didn’t stress it much. I just manually added about 1% to my FTP every week until my next test. I have been riding 20 hours a week for years now, and even I suffered from the time off like that.
This year (and ramp tests only, I’ve done a few long ones to check):
12 Oct 174
22 Aug 233
3 Aug 229
[rowing]
6 April 219 (here I was overtrained)
13 March 238
14 Feb 227
12 Jan 222
I’m sure you’re right about not worrying - I have all winter to get my fitness back up. But as someine into data I just find it a bit weird.
Op, that’s a pretty long break. Most breaks are like 1 -2 weeks off a season. You are probably seeing accurate results, tho they are surprising.
If you had really robust fitness, you might have had less of a drop (the data you share suggests you got on the bike in Jan and essentially maintained that fitness until your break with subtle bounces up and down on the tests). The lower your general fitness is, the higher then % increase you will experience in a short period of time but also the quicker it will fall when you stop. I think you can get back to your prior level in like 6-12 weeks of training or less.
If you had consistently trained for a year or two +, I wouldn’t expect such a large % decrease in a break like that.
For example, I trained and raced for about 4 yrs. Then took 1-2 years off ( stayed fit but not cycling or high volume endurance activities). Came back at about 7-10% less fitness than I had at my peak (in absolute power - not w/kg). Got approximately back to the level in 6-9mo. It took me those full 4 yrs to bump my ftp up 15-20% tho (starting at a relatively high level from other sports).
Well tbh that’s also why I’m surprised. I’m quite new to cycling but not new to endurance sport or seasonal training. I’ve been rowing competitively for more than a decade and I’ve often had fairly lengthy break after the rowing season ends in late July. When I’ve restarted training the first tests were always within a predictable range for me. As for going further upwards from my usual range of 225-235, that remains to be seen. Given the time I have to train and my age, I’m not sure I will see huge further increases from that baseline, but perhaps I’ll prove myself wrong. I’m less interested in rowing these days, so perhaps a more specific focus on cycling will pay off.
Might be but when I tried them (ramp tests) for a while every subsequent one went down, whether I am that 7.5% or my handling of ERG isn’t good I don’t know for certain. I think my first ramp test was 270w and my last one was 227w or less. On a completely mis paced 20min test my FTP comes out at 250 w so I set my FTP to that mid season. When I get the 20 min test right though its just over 280w.
If you’re anything like me, in a few seasons it will be the same. I know my FTP will mostly fluctuate around 270W now on or off season, and I think that came after about three years of increases.
Do you monitor HR, and if so is it fairly consistent and stable? It can also provide valuable information. And FWIW I find it better to focus on training by HR when returning to training after a break.
That and the previous suggestion regarding use of the same power meter. And when different, determining the difference. And doing a factory reset or advanced spindown or calibration of the trainer.
Hm, that’s interesting. Much of my training over the summer was focused on very long distances. I did a lab assessment in September which revealed very low lactate production and I did wonder whether that would affect my high-intensity work. Anyway, I’m working more on the top end now, so hopefully it will come back up.