On Monday, I did a 60-minute class in 65. Today, I did a 90-minute class in 80. It was 80 minutes of pedaling, with 48 minutes of that devoted to intervals of varying intensity, with 8 minutes of warming up, which is often harder than the intervals themselves. Today's warm-up was on par with the hard efforts. Riding with focus, which means concentrating on breathing and pedal stroke, I'd say nothing today exceeded 7 on 1-10 perceived exertion scale. Riding absent-mindedly, the high cadence, mid-zone 3 efforts would have reached 8 on PE scale. I was focused most of the time. Skipped the last 153-minute interval, as I had to return to work.