Fitspiration (Fitspo) is a social media trend that uses photos and quotes to depict idealized bodies as desirable and achievable through extreme exercise and eating practices. Exposure to, and high believability of fitspo media is associated with negative affect and body dissatisfaction. When internalized, the extremes promoted in fitspo may encourage exaggerated or biased thinking (i.e., cognitive errors). It is unclear whether cognitive errors are related to or impact how fitspiration is perceived. The purpose of this study was to examine whether fitspo-related cognitive errors (FCEs), explicit and implicit evaluations, and their interactions positively predict the believability of fitspo media. Self-identified women (N=136, M=22.46, SD=3.34) and men (N=152, M=24.25, SD=4.0) between the ages of 18 to 65 completed an online survey measuring demographics, FCEs, and physical activity. Participants were shown fitspo media, rated its’ believability, and stated up to five thoughts they had about the media (coded into anti- or pro-fitspo comments). Finally, they completed an implicit association task that paired fitspo with “good” or “bad” descriptors. Men and women were shown gender-specific fitspo and were analyzed separately. For both, explicit pro and anti-message comments significantly predicted the believability of fitspo messages, but their interactions did not (R2men=.27, p<.001; R2women=.17, p<.001). For men, FCEs predicted believability (b=.274, p<.01), whereas implicit evaluations predicted believability for women (b=-.184, p<.05). High fitspo believability may lead to maladaptive thoughts and behaviors. Men and women may process fitspo believability differently, however, future studies should experimentally test this.