The aim of this study was to develop a new self-report instrument to assess experiences of shame, guilt, authentic pride, and hubristic pride in a fitness context.In Study 1, 41 potential items were developed and assessed for item quality and comprehension. In Study 2, a panel of experts (N = 8; M = 10.55, SD = 6.49 years of experience) assessed the scale and items for validity evidence based on content. Participants in Study 3 (N = 435) completed the Body-related Self-Conscious Emotions Fitness instrument (BSE-FIT) and other established self-report measures of body image, personality, emotion, and behavior. A subset of participants (n = 38; 38% male) in Study 3 completed a 2-week follow-up.The BSE-FIT subscale scores demonstrated evidence for internal consistency, temporal stability over a 2-week period, concurrent, convergent, and discriminant validity. A 4-factor conceptualization of the instrument was supported.Overall, the final 16-item BSE-FIT instrument shows promise as a new instrument for assessing shame, guilt, and authentic and hubristic facets of pride in fitness contexts.