Charles Kyle wrote Hard workout. I really took it to my limits today. Did 2 x 20 > 240w. My plan was to decrease my cadence to 85-90 (instead of 90-95) to see how it would compare to the other 5 - 20 minute workouts I have done. My first 20 minute was average power of 284, cadence 88, HR 163. This was a little too hard. My second was 262, cad 87, HR 163. I completed the workout with Microbursts of > 150% of FTP (approx 420w) I kept them all above 375. BUT those were hard after a 40 minute nut buster. Looking at the data of the last 7 - 20 minute effort, it would appear as if I can sustain a cadence of 88, giving a power output of 284w while the heart rate only averages 163. Garmin Edge 705 EDGE705 ***