I like to think of IF as measuring the smoothness of your ride. If you ride steady 200 watts and it doesn't change for an hour, then your IF would be 1.0. If you do a lot of surges of say 200 watts, 300 watts, 100 watts, etc., then your IF will be something above 1.0. Like 1.4. Obviously those numbers are for demo purposes only.

NP is your average power and IF measured together. So if you took the above example and rode 200 watts for 1 hour and your IF was 1.0, then your NP would be 200 watts. To me it shows how hard you rode. You may only have an average of 175 watts, but your NP is 200 cause you had some really hard climbs thrown in during the ride.

I just watch current power and try to ride steady.