Virtual reality (VR) exergames provide enjoyable, immersive workouts, yet there is still a lack of knowledge about how to design these games effectively to unlock their potential. This paper investigates (i) which game elements (basic mechanics of games) contribute to player inspiration (a state-related form of motivation) and (ii) how inspiration influences players' long-term use. To answer these questions, we followed a mixed-methods design. In Study 1, we used an iterative approach to identify the most important VR exergames and their relevant game elements. Based on these findings, in Study 2, we created a survey that we sent to Beat Saber players (N=256). The results showed that nine game elements influence inspired by playing Beat Saber, and inspired to do physical exercise partially mediates the relationship between inspired by playing Beat Saber and long-term use. We conclude with implications that can inform future development in this field.