Power
NP (Normalized Power)
A weighted average of power that reflects the physiological cost of a variable-intensity ride.
Normalized Power (NP) is a weighted average of your power output that better reflects the physiological cost of a ride than simple average power does. It exists because the body responds disproportionately to harder efforts.
How it is calculated
- Smooth the power data with a 30-second rolling average.
- Raise each smoothed value to the 4th power.
- Average those values.
- Take the 4th root.
The 4th-power weighting makes higher-power moments count much more — exactly the way they cost your body more.
Why it matters
NP is the basis for IF, TSS, and load calculations. On a flat solo ride, NP and average power will be very close. On a punchy group ride, NP can be 30–50W higher than average power because of the surges.
Common misconceptions
- NP is not your "real" average power. It is an estimate of how an equivalent steady ride would have felt.
- NP for short, very hard efforts (under 20 minutes) is unreliable — the smoothing window matters less in short windows.
- A higher NP/avg ratio is not "better." It just means the ride was variable.
Related concepts
FTP, IF, TSS.