Making a kilometer blurry
Join Date: May 2006
Location: Austin (near TX)
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Learn to judge your rate of perceived exertion accurately for durations under 10 minutes. Before a power meter, I learned to do this by doing hill repeats with negative time splits, then tightening the spread. Initially, there would be a 30 second spread between my first and last times. As I learned the sensations better, I got it to where I could do six 5' hill repeats, each one faster than or equal to the previous, and only have 10 seconds between the first and last. Once you have that dialed in, you have a pretty consistent comparative power meter built in that you can use for the ~5' type interval durations.
For longer stuff, HR is reasonable. You have to combine RPE and realize that RPE is going to ramp for steady power, and so is HR.
For shorter stuff, again, use RPE. For standard anaerobic intervals, I generally do the entire interval at RPE 9, regardless of power -- so you really don't need power for the workouts, but it helps to track improvements or losses due to cumulative training fatigue.