This study investigated whether exercise and physical activity identity are conceptually distinct factors. Undergraduate students (N = 647; M[subscript age] = 19.54 ± 1.86 years; 61% female) completed an online survey including the Exercise Identity Scale and a modified physical activity version. Confirmatory factor analysis largely supported a 4-factor model consisting of physical activity and exercise role identity and beliefs. Despite some evidence of multidimensionality from a bifactor model, 86% of the variance was captured by a general identity factor, indicating unidimensionality across both domains (i.e. physical activity versus exercise identity) and dimensions (i.e. role identity versus beliefs). Collectively, these findings suggest that exercise and physical activity identity may represent a unitary construct. Further research is needed to determine the best factor structure for these identities, especially in more diverse samples. Researchers are strongly encouraged to select an identity instrument that is congruent with their outcome of interest moving forward.