The present study experimentally examined the effects of viewing Instagram images of fitspiration on body dissatisfaction, mood, and exercise behaviour among young women. Further, the study investigated if exercise engagement following exposure to fitspiration images could mitigate any negative effects from image exposure. Participants were 108 women, aged 17-25 years, who were randomly assigned to a 2 (image type: fitspiration, travel inspiration) × 2 (activity type: exercise, quiet rest) between groups design. State body dissatisfaction and mood were assessed at baseline, following image exposure, and following participation in 10 min of walking or quiet rest. Results demonstrated that exposure to fitspiration images led to significantly higher negative mood and body dissatisfaction relative to exposure to travel images. There was no difference in actual exercise behaviour according to image type. However, participants who exercised following exposure to fitspiration images were significantly more likely to report higher subjective exertion ratings. Overall, negative mood and body dissatisfaction decreased after both exercise and quiet rest, with no additional benefit of exercise for the fitspiration condition. These findings provide further evidence highlighting fitspiration as a potentially harmful online trend.