I wonder if someone could please explain 
I’ve been doing 40s:20s On:Off sessions.
Whilst reviewing that I noticed my average power is actually GREATER than my Normalised Power, I can’t get my head around how my NP could ever be lower than average power.
Agree that’s a little surprising - presumably it’s happening because your efforts are a bit above threshold, but your rest periods are a long way below it - and I believe normalised power is based on scaling your actual power according to the square of intensity (which is the distance from FTP).
How long were your rest periods between the sets of 40/20s, and how hard were the rest periods?
^ interesting. … didn’t know that (the different treatment of very short intervals)
As TP says, you shouldn’t even look at NP for any effort less than at least 20 minutes long. It’s stupid that they even provide it.
I was only doing very short efforts, 40 sec on 20 sec off so I now understand if TR’s blog is correct. I was baffled as to how a NP figure could be lower than an average across that timed segment especially after the inevitable non-erg-mode front loaded surging.
Thanks for the input & responses.
I actually have the same ‘issue’, but with a 20 min ftp test:
Although only 1 watt difference, it’s also roughly 1 watt difference in defining my ftp (i know very neglible, but i want to be correct 
)
Your Power meter error is around 2% so 1W is completely not important in grand scheme of things 
Yes, but the question remains the same: why is NP lower than average power?
(And an FTP of 305 looks way better on your resumé than 304 )
NP is higher because your power was more variable than an average of 304. I had an extreme example racing Sea Otter Circuit race last year. My NP was something like 346 while my average was under 300. I forget the exact values but, if you know the course you’d understand why. NP for 20 minutes is silly. Use average.
Yeah, but in this case it’s lower, and i don’t get it because above article refers to very short intervals, not to 20 minute ones
That screenshot is a 40 second duration.
Yes, the OP showed a screenshot of a very short duration, which was discussed earlier - with cautions around NP not being valid for very short intervals. Now @TmDrssrt has observed the same effect, but over a 20 minute ride.
Because you have 20 min effort and TP states:
“Normalized power is generally considered invalid for durations less than 20 minutes. It used to be hidden in both WKO and TrainingPeaks, but we had a great deal of people asking to see it despite the invalidity of the data.”
So probably little stochastic effort and it is it.
Cheers - it was 40 sec on 20 sec off - so well inside TP’s 20 min assessment.
