This study was designed to investigate self-objectification, its theoretical consequences, and its relationship to reasons for exercise within a fitness center environment. Sixty female aerobic instructors and 97 female aerobic participants, who ranged in age from 18 to 45 years, completed questionnaire measures of self-objectification, reasons for exercise, body dissatisfaction, and disordered eating. Increased self-objectification (and self-surveillance) was related to disordered eating symptomatology, body dissatisfaction, and appearance-related reasons for exercise. Aerobic instructors scored significantly lower on self-objectification, body dissatisfaction, and disordered eating than did aerobic participants, and they exercised more for enjoyment and less for appearance-related reasons. For aerobic participants, location of exercise (inside or outside the fitness center) moderated the relationship between frequency of exercise and self-objectification, such that exercising within fitness centers was associated with relatively higher self-objectification. Higher levels of self-objectification were also related to wearing tighter exercise clothing. These results support the general model of Objectification Theory, and provide practical implications for women who exercise within objectifying environments.