Fitness tracking devices are getting smarter. They're going to have to get a lot smarter if they are going to be powerful tools in your quest to be fit. But how much more "smart" do we really want them to get? Today they keep track of your steps and heart rate, but if your fitness tracker "knew" how you were thinking and whether you were saying things to yourself that are de-motivating ("ll never get in shape anyway") it might be more effective in getting you off the couch. But do you want it to have this information?