How would they put the commercials into the mirror?
Lets see; My PC has a 46" monitor, looks like a stereo component (read no association with work), it does require some brain effort to read the guide and choose a channel with the remote. But the fact that the wife can manage it, mean that it has to be pretty close to zero brain effort.
Of course because it is a PVR it is never shut completely off, so I would say normal 'boot time', that is the time it takes for it so wake from sleep is indeed faster than the power on cycle of the LCD TV connected to it.
There *are* a lot of cards out there with a HDMI on them, more ever day. These cards also have an internal header to connect the video card to the SPDIF header on your motherboard (or other audio card with a SPDIF header). So they do indeed carry audio.
I think the best (or at least the most entertaining) way to do it would be a variable rate that changed every day. You could even use the different gravity to help focus your exercise routine. I imagine a one quarter gravity day when you are taking a day of rest would be kind relaxing.
Work expands to fill the time available. -- Cyril Northcote Parkinson, "The Economist", 1955