In this research, the relationship between perceived stress, joy in physical activity, barriers and internalising symptoms was investigated. Based on previous literature which suggests that enjoyment is an important factor in predicting physical activity and the impact of stress in reducing physical activity, it was hypothesised that people who score higher on internalising symptoms  and report higher levels of stress would perceive more barriers to physical activity, resulting in diminished joy in physical activity. The sample consisted of 118 undergraduate psychology students at the University of Amsterdam. To explore if internalising symptoms moderate the impact of stress and barriers on joy in physical activity the Perceived Stress Scale (PSS), the Strengths and Difficulties Questionnaire (SDQ), the Regular Physical Exercise Adherence Scale (REPEAS), and the Physical Activity Enjoyment Scale (PACES-S) were used. Data was analysed using a moderated mediation model 7 from PROCESS v4.2. The results of the analysis showed a significant relationship between perceived stress and barriers to physical activity. However, the relationship between perceived barriers and perceived stress on joy in physical activity was not significant. Moreover, internalising symptoms were not found to moderate the relationship between stress, barriers, and joy in physical activity. These findings highlight the need for stress management and barrier reduction strategies to promote physical activity. Future research should explore other factor contributing to the joy of physical activity.