Whenever I find myself thinking about my exercise (ie: running) and I'm tired, I end up talking myself out of it. If I stop my mind chatter and go thru the motions, I get myself out there and am glad for it. The less I think about it, the more I do it.
I love Tae Kwon Do and rarely "think" about talking myself out of it. Running isn't my first love, but I do love the races. It's what keeps me going but I can easily talk myself out of a run by thinking to much about it, even if it isn't negative thoughts. Just something I've learned about myself