Two cross-sectional studies investigated the effects of competition and cooperation with virtual players on exercise performance in an immersive virtual reality (VR) cycle exergame. Study 1 examined the effects of: (1) self-competition whereby participants played the exergame while competing against a replay of their previous exergame session (Ghost condition), and (2) playing the exergame with a virtual trainer present (Trainer condition) on distance travelled and calories expended while cycling. Study 2 examined the effects of (1) competition with a virtual trainer system (Competitive condition) and (2) cooperation with a virtual trainer system (Cooperative condition). Post exergame enjoyment and motivation were also assessed. The results of Study 1 showed that the trainer system elicited a lesser distance travelled than when playing with a ghost or on one’s own. These results also showed that competing against a ghost was more enjoyable than playing on one’s own or with the virtual trainer. There was no significant difference between the participants’ rated enjoyment and motivation and their distance travelled or calories burned. The findings of Study 2 showed that the competitive trainer elicited a greater distance travelled and caloric expenditure, and was rated as more motivating. As in Study 1, enjoyment and motivation were not correlated with distance travelled and calories burned. Conclusion Taken together, these results demonstrate that a competitive experience in exergaming is an effective tool to elicit higher levels of exercise from the user, and can be achieved through virtual substitutes for another human player.