Hi,
Is there a link where I could read why ramp tests are not reliable indicators of fitness? I’m quite interested in this topic.
Thanks!
A RAMP test estimates the amount of watts a cyclist can sustain for 40-70 minutes (FTP).
So it’s basically an estimate of an estimate. 
You can certainly use RAMP tests to check FTP and verify your progress, but it’s only one facet of your overall fitness and capabilities.
Here are some Xert links that discuss this topic. You can find posts on other forums/blogs by searching the Internet for “FTP and RAMP tests”.
With Xert you don’t need periodic RAMP tests to estimate TP/FTP. Instead their system recalculates your fitness signature after every activity (or lack thereof over time).
I still do a RAMP test occasionally as a challenge but don’t rely on them for my fitness signature. As long as your weekly/monthly workouts include a variety of efforts (focus) your signature values should be valid.
Thank you so much, I went through some of the material you just sent me but seems that I still have a lot to read and also put pieces together.
I was asking because I did recently 20 min ftp test and also a ramp. The FTP based on those is different than what XERT estimates. Also, I suspect that my signature is not right since it doesn’t fit into the range from this chart.
and my data is as following
What I suspect is that my signature is wrong: the peak power is too low if I look on the chart and look where my HIE - 36.8kJ (should be between 1400-1800) is and also the Lower TP is too low. I am not sure if I was able to go higher on my trainer (TacX Flux S), but I will try soon to get some very high power intervals maybe it changes.
I also usually train for Half IM and not road races and I usually don’t do very short and hard intervals and lower PP might suit me more. I really don’t know 
If you’d like to try and fix your signature through further activity search the workout library for “breakthrough” and pick the standard BT workout (32 min) or version 2 (42 min).
If you haven’t ridden a BT workout before try it in ERG mode to get an idea what it does and see what PP you can achieve in that mode.
Otherwise ride the workout in resistance or slope mode and try to max out each high effort interval by switching gears and increasing cadence as necessary to hit the targets or exceed them.
Maxing out a BT workout takes a bit of practice but they are easier to perform than a RAMP or 20 minute test. An out of the saddle sprint may be necessary.
The max wattage on a Flux S is around 1500. You’ll need to be in your big ring and a small cog to hit your max power at high rpm. Be prepared to spin up quickly when the spiked intervals arrive. It is not uncommon for your outdoor PP to be higher than what you can achieve indoors on a trainer.
If the signature changes are not what you’d expect contact support@xertonline.com and ask them to review your data and adjust your signature to their recommendations.
I’d write to support directly… hard to be sure without seeing a lot more details (BT efforts, progression etc) but it looks off, especially for someone training mostly at lower intensities. They will take a look and tweak if necessary.
Not optimal to do lots of training around LTP if it’s significantly too low, so worth sorting
seems we overlapped and agree
Thanks for the advice. I’ll try the sprint and BT as you suggested soon!