In our training group, we have 6 interval sets. This week it was four sets of 30on/30 off on Zwift. This workout is the most difficult for me. This week, we had a different variation to the interval set. It was pick a big gear and do not change gears but spin the big gear easy for the off period. The big gear made the acceleration a lot harder / slower up to target power and the HR much less.
I got through my two interval sets for the week - Tuesday track and yesterday Zwift. All that is left is recovery and endurance.
Today is a recovery ride before going to the gym and destroying myself with strength training.
Edit: I expect the cadence police to show up and tell me that lower cadence does not make any difference and is a red herring.