To the end of clarifying your message - Given that people don't do, little bits of exercise throughout the day, I need some examples of exercises that I could do at my desk, or in the office kitchen or on an escalator. I simply couldn't visualise what I'd be doing, have you thought of some clever exercises I could do where I would normally feel a bit awkward about doing them? (I know a trainer that has a bunch of these). Perhaps we're just talking about exercises that people are already familiar with, lunges, squats etc. ? If that is the case then I don't think an iphone app is going to change their behaviour in which case I would be focussing on how your app is useful at the times of the day when people usually exercise.
I was thinking about this as I was going to sleep last night, and it dawned on me that what we could do is maybe have simple two-frame animations of people doing the exercises (perhaps in various locations) with the app counting in the graphics somehow.
The pelvic thrusting exercise is definitely one that people feel awkward doing in public. Hadn't thought about that angle before - one of the reasons users cited they liked CrunchFu was that they feel awkward/self-concious in gyms. That's a really good angel.
It's surprisingly effective at behaviour change, but having these other angles could be a much better hook.
