The amount of data you get from a power meter after your ride can be confusing and overwhelming when you are just starting out with a power meter. So this is how you could analyze your data to help you get faster.
Here is a list of the key Metrics to take a look at:
Normalized Power is an estimate of the power you could have if you maintained a constant power. Taking account when you are costing. The same physiological cost if power was perfectly constant.
1 hour @200w Average power is 200w and Normalized is 200w
20 mins 100w/ 20 mins 200w/ 20 mins 300w Average is 200w and Normalized is 240w
It shows that you have dug deep for the last 20 minutes
Intensity Factor is the measurement of how intense you ride was. This will tell you if you wanted to hard enough or you went easy enough. it is your normalized power/FTP = Intensity factor. An IF of 1 means you road at 100% of your FTP for 1 hour. If you see an Intensity factor of .9 that means you road at 90% of you FTP for 1 hour.
If you go for a ride and your normalized is 210w and your FTP is 280w your IF will be 0.75, 3 months later you do the same ride and you ride the same 210w and you FTP is 300 now the IF will be 0.70 making it easier. so to get fitter you will have to ride harder.
Training Stress Score tells you how you are working for that day and is a calculation of your Normalized Power, Intensity factor and ride time. you can use TSS to plan your weekly total and your monthly total. You can even plan your whole year to peak for an event or events.
Training Peaks have software to do the calculation for you.
TSS = (sec x NP® x IF®)/(FTP x 3600) x 100
Variability Index this will show you how smooth you paced was during a race or workout. A time trial should have a VI of 1.05 or less and a road race or criterium could have a VI of 1.1 or high.
normalized power/ Average power = Variability Index
These formulas are TrainingPeaks.