Lama Lab conducted a test of the trainer difficulty setting on Zwift where he rode up a hill at 100% difficulty setting and then again at 0% difficulty setting to demonstrate that the difficulty setting had no effect on the power output. Here are his results:
100% Trainer Difficulty Lap #1 - 354W [2:18]
0% Trainer Difficulty Lap #2 - 352W [2:20]
I understand that on the second lap (0%) the force applied on the pedals was less while the rpms increased keeping the power the same. So it took the same power and the same time to climb the hill proving that the difficulty setting had no effect.
But if he applied the same power and the resistance was less (gradient) on the second lap, wouldn’t he had gone faster? Does anybody know how Zwift calculates power and speed?