According to the formula 128 is my max, so on goes the heart rate monitor strap, bike on the trainer, TV set to an old Paris-Roubaix DVD (sorry, CK), clip in an spin away.
Way tough to keep the HR down
shift to an easier gear... still too high
small chain-ring... still too high
switch the TV to a cooking show... still too high
switch to Seinfeld reruns... still too high
get off the bike and on the couch... 121! Bingo, we have a winner
I did hit 135 when I got up and headed for the 'fridge to get make a sandwich but I walked slow going back to the couch and kept it under 125 most the time.
Based on my new training regiment I'm gonna thrash the other old guys next year and not spend a minute on my bike all winter ;^)
Seriously I did an hour and kept it 120-130 and was surprised at a couple things:
1) It still felt like a decent workout
2) I was not as bored as I feared
3) There's still a bunch of sweat generated