Exercising with someone is also an great way to socialize if you're a quiet person, and ill-at-ease with small talk. Pauses in conversation are natural when people are breathing heavily, there's always at least one shared topic you can talk about, and the exertion tends to make people more cheerful.
"Cryonics has a 95% chance of failure, by my estimation; it would be downright /embarrassing/ to die on the day before real immortality is discovered. Thus, I want to improve my general health and longevity."
That thought has gotten me through three weeks of gradually increasing exercise and diet improvement (I'm eating an apple right now) - but my enthusiasm is starting to flag. So I'm looking for new thoughts that will help me keep going, and keep improving. A few possibilities that I've thought of:
Pride: "If I'm so smart, then I should be able to do /better/ than those other people who don't even know about Bayesian updates, let alone the existence of akrasia..."
Sloth: "If I stop now, it's going to be /so much/ harder and more painful to start up again, instead of just keeping on keeping on..."
Desire: "I already like hiking and camping - if I keep this up, I'll be able to carry enough weight to finally take that long trip I've occasionally considered..."
Curiosity: "I'm as geeky a nerd as you can find. I wonder how far I can hack my own body?"
Pride again: "I already keep a hiker's first-aid kit in my pocket, and make other preparations for events that happen rarely. How stupid do I have to be not to put at least that much effort into making my everyday life easier?"
Does anyone have any experience in such self-motivation? Does this set of mental tricks seem like a sufficiently viable approach? Are there any other approaches that seem worth a shot?