Power Posing is standing in such a way that you take up more space. An example of a power pose:

Power Posing

The study shows that the people who use this pose increase their testosterone levels. This makes people more prone to confidence and risk taking.

Citation: Amy Cuddy, Andy Yap, Dana Carney “Power Posing: Brief Nonverbal Displays Affect Neuroendocrine Levels and Risk Tolerance” Psychological Science October 2010 21: 1363-1368, first published on September 20, 2010