A couple of weeks ago I lay down on my office floor, and I woke up an hour later!
It was the a.m. workout.
I notice that since I added an hour of body conditioning and strength training class before the spinning class a couple days/week, I'm going to bed a good two hours earlier at night! 
Today I had some errands and little projects in mind, but after my ride, I decided to bag them for tomorrow, when there is just an hour of easy exercise on the schedule.
That said, for me, there is time and energy to do more stuff on the off days.
"The best rides are the ones where you bite off much more than you can chew, and live through it." ~ Doug Bradbury