Introduction: Physical activity and exercise have numerous physical and psychological benefits. However, some individuals persevere in exercise despite the various problems it causes – physical, emotional, social and psychological. Aim: The present study aimed to explore the effects of gender, group of exercisers and supplements on the occurrence of obligatory exercise in young adults. Another aim was to explore and present psychometric characteristics and factor structure of the Croatian version of The Obligatory Exercise Questionnaire (OEQ). Methods: The study included 124 kinesiology students and 109 recreational exercisers (107 males and 126 females) in early adulthood engaged in some kind of physical activity. The participants provided information about sociodemographic characteristics and completed The Obligatory Exercise Questionnaire. Results: Analysis of the factor structure of the Obligatory Exercise Questionnaire revealed three factors: exercise frequency and commitment, exercise preoccupation and intensity, and exercise emotionality. Obtained findings correspond to the previous modified and reduced versions of the instrument. The results of the research indicate that male participants and kinesiology students exercise more often and are more committed than females and recreational exercisers. Participants using vitamin and nutritional supplements exercise more often, are more committed and more preoccupied and exercise more intensely than those who are not using any supplements. Likewise, male students using vitamin and nutritional supplements show the highest levels of exercise emotionality. Conclusion: The results suggest that the male gender, kinesiology students, and those who use the supplements may be riskier for obligatory exercise development.