I have seen “Willpower:Rediscovering the Greatest Human Strength,” by Baumeister and Tierney referenced in the media repeatedly. I am drawing from Wired (wired.com) magazine here.
The main point is that Willpower is a finite source. It actually is taxing to use it, so you need to focus on one resolution instead of many. So don’t try to start exercising, AND dieting AND stop smoking all at once because you might crash and become discouraged on all counts. To preserve some of the will power energy you can outsource self control, too. Get a gym buddy, use Mint.com to monitor spending, or regulate distracting websites with RescueTime.com.
As Tierney explains
“People with the best self-control aren’t the ones who use it all day long. They’re people who structure their lives so they conserve it.”
I will add that it came as a shock to me when studying Chinese Medicine, that it is possible to have too much will power. It is a function of the kidney, if I’m not mistaken and if you have too much you can do yourself damage. Think of the runners you know who continue to run in spite of agonizing knee problems…