Can “power posing” held for a short time increase T, lower cortisol and improve your confidence in certain situations? Maybe. Will it alter your bodycomp or make you stronger? Unlikely, as short lived transient changes in hormones don’t tend to impact body comp or strength, and I cover that topic in my write-up on OTC “T booster” supplements HERE if interested.
However, your body language and how you carry yourself etc does have feedback to your brain and visa versa and these studies suggest elevated T and reduced cortisol as well as improved performance in those who “Power Posed.” I thought the results were interesting.