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?