Glossary · Metrics
Normalized power (NP)
Normalized power (NP) is an estimate of the steady power that would have the same physiological cost as a variable ride. Because hard surges cost disproportionately more than easy riding, NP is usually higher than average power on hilly or stop-start rides.
How it's calculated
Take a 30-second rolling average of your power, raise each value to the fourth power, average those, and take the fourth root of the result. The fourth power weights hard efforts heavily, reflecting how quickly they drain you.
Intensity factor and variability
Intensity factor (IF) is normalized power divided by FTP — an IF of 0.75 is an endurance ride, around 1.0 an hour-long time trial. The variability index, NP divided by average power, shows how steady a ride was; a well-paced time trial sits close to 1.0.