I’ve been thinking lately of the seeming discrepancy of Intensity Factor for rides (and thus training stress) being based off normalised power, and the fact that power-duration curves are presented with average power. For someone who mostly rides outdoor rather than on a trainer, I wonder if a power-duration curve using normalised power would better represent my recent / season performance considering I think I’ve seen it stated that normalised power approximates to the average power you can put out on a flat course. Do people know if there is any reason other than convention that a normalised power duration curve doesn’t seem to be a “thing”? Does anyone else think this could be a good feature for intervals.icu?
An anecdote to accompany these thoughts: I did a 20min FTP test a couple of weeks ago. 1 week later, when well rested, I did a 1hr time trial on rolling hills. I was expecting/hoping that my 1hr power would be close to my FTP, but it was 10% down. However, my normalised power was within 1% of my FTP.
I would also love to see this implemented. I know it’s inconvenient to do so for the past activities as it needs to recalculate all normalized power intervals but it would be pretty cool to have this as an option.
I also have not seen this implemented anywhere else so it would definitely be added value.
You must be talking about Quad Power. Quad power is average of every second of power raised to 4th power and then 4th root for defined time segment. This is “pure” Normalized Power.
Coggan himself says that NP is not always the best measure, and you can test this yourself by doing intervals that are 30s long. One interesting effect can be the creation of an NP-buster ride where your one hour NP, which should be plus/minus 5% of your FTP, can be much higher.
Personally I prefer Bike Score and xPower by Dr Skiba, however using 25 as the decay factor gives, IMHO, too long a decay duration.
+1. This is still one of the features that keeps me going back to the training platform I used before. We’re all aware of the limitations and debates around the concept of normalized power, but it’s always useful to put race efforts and fast group rides into perspective compared to the athlete’s own history.
