There is a great article in The New York Times describing  how placebos can enable athletes to perform better. The argument is that believing that a pill or shot will boost performance (when it really just saline) causes us to tap into a reserve of energy (mental and physical) that propels us faster and longer. Specifically, the research found that runners experienced reductions in physical effort, increased potential motivation, and improved recovery.

Could be a great tool for coaches and parents!