Bruce Diesel said:I tend to look at Normalised Power vs. Average Heartrate for similar types of rides in order to track a general improvement - kind of like the PulsePower indicator on the Computrainer. So I certainly would want to keep HR data.
Power is a reliable measure but when you involve it in a ratio with HR, you're reintroducing all of HR's variability. Power vs. time is what you should be looking at since time isn't as fussy as HR.