Abstract. Objectives Exergames can replace sedentary time spent on computer gaming with physical activity. Previous research has found exergaming to elicit light-to-moderate exercise intensity. Our primary aim was to examine the exercise intensity of a newly developed biking exergame. Methods Eight males (23.9±0.6 years) played the exergame (PLAY) and walked (WALK) on three separate occasions, with the condition counterbalanced and in random sequence within each day. They were asked to PLAY and WALK for a minimum of 15 min and then continue for as long as they wanted. We measured heart rate (HR), activity duration, caloric expenditure and subject-rated exertion and enjoyment (based on 0–10 Visual Analogue Scale, VAS). We used an average of each outcome variable across the 3 days in the analysis. Results The average intensity during PLAY (73%±10% of HRmax) was significantly higher than that during WALK (57%±7% of HRmax, p=0.01). Participants spent 12.5±5.3 min at 80%–89% of HRmax and 5.5±4.6 min at ≥90% of HRmax during PLAY, whereas intensity during WALK was ≤72% of HRmax. The duration of PLAY was 44.3±0.7 min and of WALK 17.0±0.7 min (p=0.01). The relative energy expenditure during PLAY was 7.6±0.7 kcal/min and during WALK 6.2±0.3 kcal/min (p\textless0.01). The enjoyment of PLAY (VAS 8.7±0.1) was higher than that of WALK (VAS 3.9±1.8, p=0.01). Conclusions Exergaming can be an innovative way of enjoyable high-intensity training.