What is normalized power?

Normalized Power is a metric that is used in cycling to account for the variable effort required during a ride or race. It is calculated by taking the fourth root of the average power output over a given time period (usually one hour), which is then multiplied by 0.9. This calculation effectively weights the harder efforts during a ride or race, giving a more accurate representation of the effort required than just looking at average power. Normalized Power is often used in conjunction with Functional Threshold Power (FTP) to set training zones and monitor improvements in fitness.