You have probably seen the promise: stand like Wonder Woman for two minutes before a presentation, raise your testosterone, lower your stress hormones, and walk into the room feeling powerful. Fake it until you make it. Change your body, change your mind.
The promise was irresistible. It offered a simple confidence hack for a job interview, pitch, or keynote.
Then researchers kept testing the hormone story. In a controlled 2019 study, three repeated two-minute periods in an expansive pose produced no different testosterone, cortisol, or progesterone response from constrictive poses.
Power posing may change how some people feel in the moment. This study found no evidence that it changed the three hormones measured.
In other words, the viral version of power posing does not work as advertised.
What the researchers tested
Hannah Metzler and Julie Grèzes recruited 82 male participants. Participants repeatedly held either expansive or constrictive postures for two-minute periods.
The researchers collected multiple saliva samples and measured:
- Testosterone
- Cortisol
- Progesterone
They included progesterone because it has been associated with affiliation, offering another test of whether expansive and constrictive postures produced different hormonal patterns.
What they found
Hormone levels changed over the course of the session, but the changes did not differ between the expansive- and constrictive-posture groups.
The study found no evidence that posture produced the predicted effect on testosterone, cortisol, or progesterone.
This result joined several earlier studies that had failed to reproduce the original hormone findings. It is strong evidence against treating power poses as a reliable way to manipulate those hormones.
What the study does not show
“Power posing does nothing” is broader than the evidence.
This experiment included only men and measured three hormones. It did not test every possible behaviour, feeling, or speaking outcome. The authors also noted that a meta-analysis had found effects on self-reported feelings of power or control, even while evidence for hormonal and behavioural effects was weak or absent.
If an expansive posture helps someone feel ready, that personal routine may still be useful. What is not justified is claiming that it reliably changes testosterone or cortisol.
What to do before speaking
Use posture for function
Stand in a way that makes breathing, movement, and projection easy. You do not need a hormonal explanation for comfortable posture to be useful.
Prepare the first minute
Uncertainty creates work. Knowing your opening point and first example reduces the number of decisions you must make under pressure.
Reframe arousal carefully
A separate randomized experiment found that saying “I am excited” before a speech produced better ratings than saying “I am calm.” That is evidence for a specific reappraisal, not a general body hack.
Build confidence from repetitions
Practise, review one observable issue, and try again. Confidence grounded in evidence from your own attempts is less fragile than confidence borrowed from a viral promise.
The bottom line
The power-pose promise spread because it offered what anxious speakers want most: confidence without the work of becoming confident.
The hormone story did not survive this test. Expansive posture produced no different testosterone, cortisol, or progesterone response from constrictive posture.
That does not make posture irrelevant. Stand in a way that helps you breathe, move, and speak. Just do not mistake a useful stance for a biological shortcut.
Put this into practice
Use impromptu speaking practice to prepare the thing that matters after the pose ends: a clear answer delivered under time pressure.