Effectiveness of self-competitive gamification designs in VR exergames. Pilot study results from a 6-week training intervention with senior users.
Authors: Buchem Ilona , Vorwerg Susan , Stamm Oskar 
Published: July 2022

VR exergames, as a form of serious games for physical exercising, have been used to increase motivation to exercise, support long-term adherence and improve health-related outcomes in different populations including senior users [1]. Typically, gamification designs in exergames have incorporated such elements as points, badges, leader boards, levels of difficulty and time limits to benefit users [2]. Gamification designs in exergames have also used the mechanics of both social competition and self-competition to enhance training outcomes. While competition in exergames may be experienced as excitement and thrill by users with a heightened competitive drive to win, it may at the same time negatively affect intrinsic motivation and outcomes of less fit and/or less competitive users [3]. Therefore, it has been argued that self-competition in exergames is a more fair approach as it gives less fit users a better chance to improve one's previous performance and resist quitting. This paper presents the result from a pilot study, in which two prototypes of the VR exergame “ballgame” were tested with 23 users aged 75.8 years (SD: 4.7) during a 6-week training intervention. The ballgame was designed for single-players and incorporated self-competition mechanisms. The VR training system with exergames was designed in the R&D project “bewARe” dedicated to a sensor-supported movement training for senior users and founded by the German Ministry of Research and Education. The 6-week training intervention included a set of VR exergames ranging from strength endurance to endurance exercises like dancing or ballgames. The study investigated the effectiveness of the two designs of the ballgame, using the hit rate as a metric. In ballgame 1 (B1), users had to throw a virtual ball precisely into a ring held by the virtual trainer “Anna”. The users were asked to throw the ball alternately with the right and left hand in a time of 2.5 minutes. The virtual trainer was holding the ring in her hands and changed its position from time to time. In ballgame 2 (B2), the task was to throw the balls against a wall with the right or left hand as fast as possible within 1.0 minute. During B2 the virtual trainer was not interacting with the user through synchronised movement as opposed to B1. All hits to the ring in B1 and against the wall in B2 were counted and displayed for the user in the VR hit counter. The two ball games (B1 and B2) were repeated in 2 to 3 rounds during a training session. The primary goal of our research was to evaluate to what extent the different self-competition designs enhance the improvement of one’s own performance over time. The study was part of the 6-week exergame training for senior patients with hypertension and took place in the laboratory of the Geriatrics Research Group at Charité Universitätsmedizin Berlin. During the period of six weeks, participants had two training sessions each week. Each session lasted approx. 30 minutes and had moderate intensity (40-60% of heart rate reserve). Users were immersed in VR exergames by wearing an HTC Vive Pro headset and interacted using HTC controllers. The study was approved by the Ethics Committee of the Charité (No. EA1/019/20).Mean values were calculated for each training session. Mean hits were 26.46 (SD: 7.02) in B1 and 22.71 (SD: 6.11) in B2. A repeated-measures ANOVA with Greenhouse-Geisser correction showed that over the entire course of training, the average number of hits differed significantly for both ball game variants (B1: F(2.58, 43.90) = 67.09, p<0.001, partial Eta squared = 0.80; B2: F(1.46, 23.32) = 35.90, p<0.001, partial Eta squared = 0.69). From training session 1 to training session 6, the number of hits increased by 20.66 (SDF: 1.59) for B1 and by 15.55 (SDF: 2.19) for B2. Out of 23 study participants, 14 (60.9%) liked the ballgames most compared to all other exergames. The results indicate that self-competitive gamification designs in VR exergames are effective for less fit users such as senior patients with hypertension. In both versions of the ballgame users improved their performance over time as the hit rate increased and the users did not quit the exergame. The paper presents the differences in the gamification designs of both prototypes and discusses possible interdependencies with the different forms of interaction with the virtual trainer and the effects of repeated practice over time. We conclude with recommendations for further research.References[1] Larsen, L.H. et al. (2013). The Physical Effect of Exergames in Healthy Elderly. A Systematic Review. Games for Health, 2(4), 205-12[2] Nor, N.N. et al. (2020). A Review of Gamification in Virtual Reality (VR) Sport. EAI Endorsed Trans. Creative Technol., 6.[3] Michael, A., & Lutteroth, C. (2020). Race Yourselves: A Longitudinal Exploration of Self-Competition Between Past, Present, and Future Performances in a VR Exergame. 2020 CHI Conference on Human Factors in Com. Sys.