SHANGHAI -- For eight weeks, approximately 180 overweight or obese Chinese teenagers, who were born in the digital age, took part in a virtual coaching program involving table tennis and soccer.

The new virtual reality (VR) sports initiative is part of China's efforts to combat adolescent obesity by utilizing the most advanced AI technology.

Adolescent obesity has become a global public health crisis, with the number of obese 5- to 19-year-olds worldwide nearly tripling in the period from 1990 to 2022. China is now prioritizing tackling teen obesity in its public health initiatives.

Faced with this challenge, some scientists are investigating whether virtual reality (VR) technology can help digitally-native teenagers reach weight-loss goals safely and effectively.

An international multidisciplinary team led by health and computer scientists from Shanghai Jiao Tong University in east China have created the world's first intelligent VR sports intervention system -- which combines AI-driven virtual coaching, motion tracking and immersive VR environments to guide users through exercise sessions.

The system, named REVERIE (Real-World Exercise and VR-Based Exercise Research in Education), features a transformer-based AI coach, trained using deep reinforcement learning, which provides real-time feedback and adapts to individual performance.

This groundbreaking intelligent tool underwent a rigorous clinical trial involving 227 overweight or obese teenagers, including a control group, with the results published in the journal Nature Medicine.

In the eight-week randomized controlled trial, the first of its kind globally, participants were divided into groups engaging in either real-world sports, namely table tennis or soccer, VR-based versions of the same sports, or a control group with no additional exercise.

Participants outside the control group received exercise intervention sessions three times a week -- in addition to their regular physical education classes at school.

Encouragingly, REVERIE has demonstrated significant potential in helping overweight and obese adolescents lose weight, improve cognitive function, and maintain long-term exercise motivation.

Both VR and real sports groups showed comparable fat loss, with VR users experiencing additional cognitive benefits, including enhanced working memory and olfactory sensitivity, according to the study.

Brain imaging revealed that VR exercise led to greater neural efficiency and plasticity, while further analysis identified unique metabolic and gut microbiome changes linked to cognitive improvements.

Notably, the VR group maintained higher exercise motivation six months after the trial, suggesting that immersive digital workouts could help increase teenagers' willingness to engage in physical activity and overcome common barriers like low engagement and social anxiety.

The system also proved safer than real sports -- with a lower injury rate.

The evidence-based study shows that the VR system holds promise as an empathetic solution in addressing the challenges of physical inactivity and obesity among adolescents.

A review article which appeared in Nature magazine commended REVERIE for offering a "novel and effective strategy" and yielding "similar, and at times superior, benefits" compared with conventional real-world sports.

"Virtual reality has evolved beyond a closed sensory simulation experiment. It now functions as a digital symphony, resonating with and subtly recalibrating the human nervous system," said the study's lead researcher Sheng Bin from Shanghai Jiao Tong University.

The term REVERIE, literally linked to virtual reality, echoes the renowned Chinese scientist Qian Xuesen's translation of VR as "reverie," which he believed would vastly enhance human perception and open up a new world.

Looking ahead, the team plans to harness the potential of VR in fostering healthier, more active lifestyles among adolescents -- thereby contributing to global efforts to improve the health of this age group.