Normalized power (NP)
Normalized power (NP) is an estimate of the steady power that would have stressed your body just as much as the variable ride you actually did. On a ride full of surges, hills and traffic lights, NP comes out higher than your average watts.
In Trimetra this is called weighted power.
What is normalized power?
The average power of a ride is an honest calculation, but a poor measure of how hard it was. Two hours steady at 200 watts and two hours alternating between 100 and 300 watts give the same average, while the second ride hits far harder. That is because stress rises more than proportionally with intensity: the peaks cost you more than the troughs give back.
NP corrects for that by letting the hard stretches weigh more than the easy ones. The result is a single number that lines up better with how hard a ride felt. For a steady time trial NP and the average sit close together; for a criterium or a technical mountain-bike ride the gap can be substantial.
What do you use NP for — and what not?
NP is meant as an intensity measure: it feeds the intensity factor (NP divided by your FTP) and through that load scores such as TSS. It is emphatically not a performance number. You cannot compare NP with your FTP test or with someone else’s average, and it is not "hidden power" that you supposedly produced.
Know the weak spots too. NP leans on a calculation model with fixed assumptions, is unreliable for short efforts of at most a few minutes, and can be inflated by rides with a lot of coasting: every second at zero watts on a descent counts differently than it does in the average. And because NP is always set against your FTP, its usefulness stands or falls with an up-to-date threshold anchor.
How Trimetra personalises this
Trimetra reads in a supplied NP, but computes your load from average power against your FTP, so that all your rides count in the same way. On variable terrain that gives a slightly lower estimate. If the app used each ride’s NP from the time, old sessions would stay frozen on the FTP of back then and your load build-up would quietly go inconsistent — and that build-up is exactly what the planner steers on.
Frequently asked questions
Why is your NP higher than your average power?
Because the hard stretches count more heavily than the easy ones: surges cost your body more than the lulls give back. On a ride full of accelerations, hills and traffic lights, NP therefore sits above your average; in an even time trial the two sit close together.
Is NP your real power?
No. NP is an intensity measure — an estimate of which constant power would have been equally taxing — not a performance number. You can’t compare it with an FTP test or someone else’s average, and it is not "hidden power" you actually produced.
When is NP unreliable?
For short efforts of at most a few minutes, for rides with a lot of coasting (every second of zero watts distorts it), and as soon as your FTP is outdated — NP is always set against your threshold anchor, after all.
Every term at a glance in the full glossary.
TSS, NP, IF, CTL, ATL and TSB are trademarks of Peaksware, LLC (TrainingPeaks). Trimetra is not affiliated with them; this page merely explains the term.