Crossfit utilizes some powerful mental tools to improve physical perforamance.
One of them is by using personal goals.
Revolutionary, you might say sarcastically.
Here's they way they work it:
Go do something. Run a mile, row 2000 meters, do 50 push-ups, whatever. Time it. Write it down.
Next time you do it, your goal is to beat that time.
The first couple of times you do that same event, generally speaking you do better. But after that it gets much harder to improve that time. You start thinking about all the ways in which you could go better. First, you start thinking about your form, how to maximize your movements at certain points during the exercise, etc. Then, you start thinking about what you ate yesterday, like that soda you drank with lunch (soda is bad, don't you know). A while later, it's what you ate last week - the dough-nuts your co-worker brought on Thursday. And after that, you start thinking about the exercises you did last week or last month that may or may not be helping you hit that specific goal.
By the time you realize that you are obsessed with all this, your body-fat percentage has dropped to 15 or so, and your Doctor cannot believe he/she is looking at the same person from a year ago.
This is why I hate quarterly or yearly goals in the business context. If you are working at something you may or may not hit a given target in that period of time. It is not the hitting of the goal that is so important, it is the trying, and the results from that effort that matter.