Effects of Tai Chi and conventional exercise on improving cognitive performance in older adults with mild cognitive impairment: Study protocol for a randomized controlled trial

Dementia is a significant global health challenge, with mild cognitive impairment (MCI) as an early possible intervention stage. Although physical exercise is widely recommended for MCI management, the comparative effects of Tai Chi versus conventional exercise on cognition in this population remain unknown. This study aims to investigate the effects of Tai Chi and conventional exercise on improving cognitive performance in older adults with MCI. This assessor-blinded, three-arm, parallel-group randomized controlled trial will enroll 312 community-dwelling Chinese adults aged ≥50 years diagnosed with MCI. Participants will be randomly allocated (1:1:1) to one of three 26-week interventions: (1) Tai Chi (n=104), (2) conventional exercise (n=104), or (3) health education control (n= 104). The Tai Chi group will receive a 24-form Yang-style Tai Chi intervention; the conventional exercise group will undergo a program comprising aerobic and muscle strengthening exercises; and the health education control group will receive structured health education classes. All interventions will be delivered in twice-weekly 90-minute sessions for 26 weeks. The primary outcome is the Hong Kong version of the Montreal Cognitive Assessment (HK-MoCA) score. Secondary outcomes include neurocognitive function, subjective cognition, physical performance, mood, sleep quality, and quality of life. Outcomes will be assessed at baseline, post-intervention (week 26), and follow-up (week 52), and data analysis will adopt the intention-to-treat (ITT) principle. This study will compare the effects of Tai Chi and conventional exercise on improving cognitive performance in older adults with MCI. The results will contribute to the evidence-based exercise recommendations for MCI management and dementia prevention. • Randomized control trial comparing Tai Chi and conventional exercise for MCI • Adequately statistically powered study with 315 participants, 26-week intervention and 52-week follow-up • Adopts comprehensive both objective and subjective cognitive measures