Yesterday I did a blood lactate test and then a VO2 max test and got the numbers I expected but I was disapointed but not surprised that Xert did not reflect much closer to breakthrough effort than it did
My FTP was 212 with Xert thinking it was 218-220. I expected that if I took a 20’ test I would be just over 220-225.
LT2 was between 220-230 and interestingly that corresponded with a HR of 138. I always know that when I hit 138 I am working at a close to threshold effort.
Whilst I did the best I could on the VO2 test I know I should have done more as I only got to 154 HR when I can achieve 159 (and have done fairly recently). However I do very little training at that level of intensity and do not ride outside that much.
So overall the numbers were accurate and if I look at the diagram I think that reflects the truth. If I had been able to push for a bit more - say another 20w for 1 minute I might well have seen MPA drop and my effort meet it.
So no complaints about Xert, just a recognition that I shoudl be able to do more.
I don’t have a real concrete answer, but how much riding history do you have on Xert? If your HIE is a bit too high to reality, then MPA should’ve been drained quicker and perhaps a BT?
Also be aware that you spend ~15 min of riding at a fairly moderate activity prior to starting an incremental ramp to exhaustion. It’s quite possible that you weren’t fully recovered by the time the second effort started. Also, were you free to select your cadence, or were you required to stay clamped at a certain cadence? There is also some mental aspect to fully pushing yourself on a VO2ramp. I usually try to count down from 30s when I get a real strong urge to quit pedaling.
No data for the LT then VO2 ramp, but I have done multiple ramp tests in TrainerRoad. On some I have crushed the test and achieved a breakthrough, or been very close, and on others, underperformed.
Here is one where I did give everything I had (got an FTP increase in TR and a breakthrough in Xert):
Here is one where I felt like I underperformed, and Xert agreed:
If I feel/see that I underperform on a test, whether ramp or an outside climb or something, it’s just motivation to repeat it a few days later and crush it (better fueling, motivation, etc). But I am testing in my basement or outside for essentially free, where I know that LT + VO2 in a lab can be expensive (I have done it), so you really want to get your money’s worth the first time!
ETA: Now as I look at these, I see my starting signature was different between these tests. My Peak Power on the first was probably too low, making the breakthrough easier.
