The game of roundnet (spikeball) is a trend sport that has gained much popularity in leisure time activity in recent years. However, no scientific studies dealing with this trend sport are published yet. The aim of this study was to evaluate the physiological demand of male roundnet players during a roundnet match. Therefore, 12 experienced male roundnet players were recruited. In a pre-experimental test, all participants conducted a ramp-based treadmill test with spirometric measurements. Further, lactate concentrations, velocity and heart rate (HR) were measured. In a subsequent field test, participants conducted a roundnet game in accordance with the official rules. During that field test, the following parameters were measured: Average and maximum HR, lactate concentrations, step count, steps per minute, playing time and rate of perceived exertion (RPE). Results of the pre-experimental test reveal that participants reached a maximum running speed of 5.1±0.2 m/s, a maximum HRof 190.4±7.2 bpm and a VO2max of 55.8±4.2 ml/min/kg. Results of the field test showed that participants reached a maximum HR of 159.7±7.9 bpm corresponding to 83.9±3.6% of the participant’s maximum HR. Average HR was 133.6±9.4 bpm corresponding to 70.1±4.2% of the participant’s maximum HR. Participants reached a mean lactate concentration of 1.2±0.2 mmol/l and a RPE score of 13.2±1.2. The mean playing time of one set was 10.8±0.8 minutes. On average, 790.5±125.2 steps were measured during one set equaling 73.1±11.6 steps per minute. To conclude, this study first time presents game characteristics and the physiological demand of the trend sport roundnet. Results indicate that the physiological demand can be described as moderate as none of the measured parameters reaches disproportionately high values.