Effectiveness of Metaverse Space-Based Exercise Video Distribution in Young Adults: Randomized Controlled Trial.

BACKGROUND: In response to the serious lack of physical activity among young adults, recent attempts have been made to encourage young people to exercise through exercise video distribution. However, merely distributing videos does not lead to improved physical activity levels. Metaverse space, which enables web-based interaction through avatars, allows users to watch exercise videos in the same space as other avatars. OBJECTIVE: This study explored whether exercise video distribution using metaverse space is effective in improving physical activity levels, along with mental health and locomotive function, among young people. METHODS: In this parallel-group randomized controlled trial participants were recruited using printed poster displays. A total of 48 young adults aged between 18 and 30 years were assigned to 3 groups of 16 each: the metaverse, YouTube, and control group. To encourage exercise, the metaverse group was given an exercise video each week with a load of around 4-8 metabolic equivalents of tasks (METs) for 8 videos delivered in the metaverse space. The YouTube group was sent a URL on YouTube every week to view exercise videos with the same content as the metaverse group. The control group was given no special instructions. The intervention period was 8 weeks. Pre- and postintervention physical activity, well-being, locomotive syndrome risk tests, and social capital were measured. Although this study was not blinded to the participants, the measurers did not know to which group the participants belonged. Mixed model repeated-measures analyses and a post hoc Wilcoxon signed rank sum test were performed to detect the effects of the intervention in all groups. RESULTS: The results of the mixed model repeated-measures analyses showed a significant interaction between groups and before and after the intervention for total physical activity (metaverse group: pre 737.1, SD 609.5 METs/week, post 1575.4, SD 1071.8 METs/week; YouTube group: pre 661.7, SD 710.7 METs/week, post 911.9, SD 1103.3 METs/week; and control group: pre 930.6, SD 665.1 METs/week, post 844.7, SD 701.8 METs/week; P=.04) but none for the indicators of well-being (P=.40), locomotive function scale (P=.17), and social capital (P=.23). A post hoc test showed a significant increase in physical activity in the metaverse group before and after the intervention (P=.006). CONCLUSIONS: This study is the first to show that delivering exercise videos through metaverse space can increase physical activity in young adults by providing a gathering space for individuals similarly motivated for exercise practice. This way, the sense of isolation during exercise is reduced compared with merely distributing videos on YouTube. The use of metaverse space in health promotion is likely to spread, and this study provides a useful reference for its exploration. TRIAL REGISTRATION: ClinicalTrials.gov NCT06019156; https://ichgcp.net/clinical-trials-registry/NCT06019156.

In vitro production of insulin-responsive skeletal muscle tissue from mouse embryonic stem cells by spermine-induced differentiation method.

The treatment of an embryoid body with spermine for a short duration can trigger the generation of a 3-dimensional multilayer myotube sheet (MMTS) that shows pulsatile activity. MMTS was previously characterized as a model of skeletal muscle tissue. In the present work, the insulin responsiveness of MMTS was investigated because it is an essential function for a model of skeletal muscle. The glucose uptake activity of MMTS was analyzed by confocal microscopy using fluorescent glucose analogs, namely 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-D-glucose (2-NBDG) and its L-glucose counterpart, 2-NBDLG. The specific uptake rate of glucose was estimated from the difference between the fluorescent signals of 2-NBDG and 2-NBDLG. It was enhanced by insulin stimulation to 3.6 times higher than the control without insulin, and this insulin responsiveness was maintained for 5 days. The advantages of the 3-dimensional structure of MMTS are discussed in the contexts of its potential in vivo and in vitro uses.

Concentration-dependent effects of spermine on apoptosis and consequent generation of multilayer myotube sheets from mouse embryoid bodies in vitro.

The concentration-dependent effect of spermine was investigated on the spermine-induced generation of multilayer myotube sheets (MMTS) from mouse embryoid bodies (EBs). During spermine treatment for 24 h, a monolayer cell sheet that had already grown radially from the periphery of an EB was exfoliated. The exfoliation was inhibited by z-VAD.fmk, indicating the occurrence of apoptosis, and inhibited also by aminoguanidine, indicating the involvement of amine oxidase. Following the exfoliation, the cell growth restarted from the fresh periphery of EB in a spermine-free medium and finally formed MMTS. To analyze the contribution of apoptosis to the cell death causing exfoliation, the numbers of apoptotic, necrotic, and 2nd apoptotic cells were counted by staining with Annexin V-Cyanine-3 (AVC3) and 7-aminoactinomycin (7AAC). AVC3-positive, 7AAC-positive, and AVC3/7AAC doubly positive cells were assigned as apoptotic, necrotic, and 2nd necrotic cells, respectively. The relative number of apoptotic and 2nd necrotic cells (N A + N A/7) to the total number of dying cells (N T) was 84 ∼ 94%, which was independent of spermine concentration in the range from 0.1 to 2.0 mM. The MMTS generation rate at the final stage, however, was dependent on the spermine concentration. It was 60 ∼ 80% in the range from 0.1 to 1.5 mM, while it decreased sharply to 1% at 2 mM. This suggests another role of spermine in the MMTS generation in addition to the induction of apoptosis. This 2nd role seems to be inhibited at a spermine concentration higher than a critical limit between 1.5 and 2.0 mM.