This study examined Identity Theory hypotheses about identity-behaviour consistency. Exercise-identity strength and judgments about consistency were hypothesized to relate to perceptions of percent consistency and frequency of vigorous exercise. Identity strength and percent consistency were hypothesized to interact in their relationship with affective reactions to extent of consistency. Measures of exercise-identity strength, perceived consistency, exercise frequency, self-regulatory efficacy and consistency-related affect were completed by 528 exercisers. Exercise-identity strength and consistency judgments related to percent consistency and exercise frequency. Exercise-identity strength and percent consistency interacted in their relationship with consistency-related affect and also were related to self-regulatory efficacy.