I just completed a 68km road race on Sunday and noted that my TSS score was 210. The total race time was 1 hour 58 minutes. Normalised power was 277w.
I have only just returned to Trainer Road and hadn’t done a Ramp Test in a while. The week prior it set my FTP at 268w. About a month prior to that the ramp test was 265w. I have been zwifting a lot before jumping back on TR and my estimated FTP was more like 280 - 290w (realising zwift likely over-estimates).
Obviously there are a bunch of factors that come into play, such as surging during the race rather than a steady effort, potentially underscored in the ramp tests, [Edit: I am using Assioma DUO outside and Tacx Flux2 inside so that could easily be the difference]. But I didn’t think it was possible to have a TSS over 100 per hour, unless your FTP is set too low. I’ve only done a few workouts at 268w that I achieved, but they weren’t particularly easy.
So, should I be bumping up my FTP until I’m at my limit during workouts? Or continue as is and re-test in a couple of weeks when it’s time again.
What are the negatives of keeping a slightly lower FTP and successfully achieving each workout, versus ultimately missing out on working the “exact” zones but potentially failing workouts too. Which has a compounding (but serious) mental negative effect.
Edited re power meters.
Are you using the same power meter inside and out?
Sorry should have put that in there too. Will edit that. No, I am using Assioma DUO outside and Tacx Flux2 inside. So yes I guess that could easily be the difference. Duh (to me).
Also, the (lack of) cooling indoors could be a contributor to lower FTP indoors.
My suggestion would be to keep FTP where it is until you can re-test, and let Adaptive Training serve up workouts that are appropriately challenging.
What was the average power in the race?
First thing to do is to put your Assioma pedals on the bike you are using on the Tacx Flux and do some testing. You can compare the power files using zwiftpower’s analyse tool. Then hopefully (if Assioma have the feature) you can adjust down the power from the pedals to get them in sync with the Tacx. I have done this my self with my power meters as my power varied up to 11% from Tacx Neo to Quarq: Is it possible to adjust reported power from power meters?
Thanks. Good idea. Will do that and see if I can record the power at the same time in some way. Cheers.
A lot of people, myself included, can do better numbers outside than inside, it is fairly common. Sometimes quite a significant difference too - for me that would be more or less enough to explain the difference there.
As above there is a margin of error on the PMs.
A race can be a very stochastic effort, so the NP from the race could be a lot different to what you could actually hold for that duration (which is what NP is meant to represent) - just looking back through Zwiftpower (easy to see history there for Zwift races), I have some very high calculated NPs especially on races with hard efforts followed by recoveries (climbs at VO2 then descents for example). I think this is a pretty well known phenomenon.
I also have this - can way over perform a ramp test in races (both real world, and zwift with the exact same set up).
Regarding outside races, I don’t adjust, as I do my training inside*. I have tested my single sided 4iii against my original hammer, and it’s margin of error differences. But again I don’t really sweat it, as I really only use the hammer to train, and to be completely honest it’s often just “nice to have” data outside. For me n=1.
*I haven’t really looked at what FTP estimation does with outside unstructured work, so may be a factor going forward, particularly as I could well be racing several times a week!