http://www.nytimes.com/2010/02/04/fashion/04best.html?pagewanted=2&ref=nutrition
If you are training to reach a certain weight on the scales, you may find that your performance drops when the scales drop too low "for you"!
Quote from attached article:
Mr. Reyes said that he and Mr. Agassi learned not to let the scale rule your life. “We had a little bit of a phrase,” he said. “The weight scale to most human beings can be like a Ouija board. It can start messing with your head.”