I own the following T-shirt from Shirt.Woot!: 
It accurately describes one major aspect of why I don’t regularly exercise. Lack of motivation… and there is an unfortunate dearth of gigantic prehistoric predators around to provide such motivation.
I need some kind of distraction while exercising because, frankly, it is both painful and boring. I need something to take my mind off of what is going on, something similar to the TV screen on the ceiling when you go to the dentist. Last year I came across the courseware offered through the Teaching Company . I set myself up first with an iPod, then with a portable DVD player next to my treadmill/exercise bike, and only allowed myself to view a “lesson” (which are nicely broken up into 30 minute chunks) when I was exercising. As such things go, this was pretty successful. I completed just under 50 lessons or two complete courses in 11 months, which means on average I was exercising once a week. Far below the ten hours a day that most truly fit people seem to claim you need in order to stay healthy, but a vast amount more than zero.
Looking at 2010, I continue to need exercise, and continue to lack motivation. I have added one more mental trick through my regular use of the LiveStrong.com food and activity tracking website . I get more or less immediate “feedback” regarding my calorie input and consumption, so when I eat a bit extra I can offset that right away by exercising the same day. The graphs and visuals help trick me into thinking I’m accomplishing something, which is an important part of overcoming my negative inertia. And, although it is still very early in the process, I’m actually beginning to see a link between net calories and weight loss. In a month or two, assuming this continues, this linkage might be a significant motivator by itself.
I’m starting to think, though, that I need one more push to get on the treadmill or bike a bit more often than once a week. I have been considering installing TV sets in my exercise room, and establishing a “you can’t watch <some desirable program> unless you are exercising” rule. This has several benefits. First and foremost, it means I have to acquire a bunch of new gadgets: LCD panels, wall mounting hardware, and something to bring the DVR/Apple TV recorded programming up to the exercise room. Secondly, it is in the same vein as my already-proven “you can only watch these educational lessons when exercising” approach.
Or I could just clone myself a T-Rex or a couple of raptors. That might do the trick too…