Biathlon Training on an Unstable Platform in Non-Immersive Virtual Reality: Exercise Intensity, Enjoyment, and Flow State in Adolescents

Engaging adolescents in regular physical activity remains a major public health challenge; consequently, increasing attention is being directed toward technologies that make exercise more attractive, task-oriented, and engaging. Active video games and non-immersive virtual reality systems are particularly promising because they combine physical exertion with feedback, gamification, and movement-based interaction. This study examined whether a biathlon exergame performed on an unstable ICAROS Cloud platform using the ICAROS App can elicit favorable physiological and psychological responses in adolescents, and whether these responses depend on body position. Eighty secondary school students, including 41 girls and 39 boys, completed two 10 min Biathlon trials: one in a standing position and one in a quadruped kneeling position, with the trial order counterbalanced. The percentages of maximum heart rate (%HRmax), perceived exertion, enjoyment of physical activity, and flow state were assessed. The standing condition elicited higher exercise intensity than quadrupled kneeling (71.42 ± 9.61 vs. 62.09 ± 9.04%HRmax; p < 0.001), and was also associated with higher perceived exertion, enjoyment, and flow. Similar response patterns were observed in girls and boys. These findings highlight the potential of unstable-platform exergaming as a practical and engaging approach to technology-supported physical activity promotion in developmental ages.