Fake It To Make It

Beyond negative self-talk, I give myself positive self-talk even when it's not quite true. I tell myself throughout a tough workout that I love it and it is good for me, even as I want to quit. At the end I tell myself it felt great, even as I drag myself back to the locker room. At the end of a long training walk, even with new blisters on my feet, I tell myself it felt great to have made it that far. Rather than thinking that I must be aging or will never get more fit, I am thinking that I am somebody who loves the training and will challenge myself till I achieve new levels of fitness.
http://walking.about.com/cs/fitnesswalking/a/bepositive.htm