I rode the semi-recumbent stationary bike on my regular schedule today. This is noteworthy only because I nudged it up to level 3 for 48 minutes and lived to tell about it.
In October, I was using level at 1 for 32 minutes.
Most interesting to me is not the "distance" I went, but that my knees (my weakest link) have far less discomfort with this level and time than in they did during the lighter workouts back in October. So it would appear I am responding to the regular exercise.