Previous research investigated the effects of power poses at the behavioral, subjective, and neuroendocrine level. However, it is not clear whether the same effects would be obtained also by just imagining, rather than adopting, a power pose. We planned to investigate this question by asking 200 participants to either perform or imagine a constrictive or an expansive body posture during 2 min and then measure the effect on a gambling decision task and on felt power. We followed a sequential analysis procedure by running the first 100 participants in the performed posture condition in order to check the presence of the power posing effect. Because no effect of power poses on gambling decision or on felt power was found, we ran the remaining 100 participants also in the performed instead of the imagined condition. The results after running 200 participants confirmed that power poses did not affect gambling decision. However, participants felt more powerful after adopting an expansive pose compared to a constrictive pose. Exploratory analyses found that this effect was mainly driven by male participants. In addition, participants rated themselves as being more able to adopt the expansive body posture and they reported to put more effort in adopting the restrictive body posture. Overall, our results indicate that the effect of power poses on behavior might not be as widespread as previously thought of and suggest that moderators should be investigated carefully in future research.