Effects of Baduanjin combined with cognitive training in older adults with mild cognitive impairment of mixed etiologies: a study protocol for a randomized controlled trial

BACKGROUND: Amid the accelerating aging trend, addressing mild cognitive impairment (MCI) is critical for dementia prevention. Current evidence suggests that standalone interventions have limited efficacy, whereas combined physical‑cognitive training may yield greater benefits. However, the neurophysiological mechanisms of sequential combinations, particularly their effects on regional brain activation and functional connectivity, remain unclear. Functional near‑infrared spectroscopy (fNIRS) offers a non‑invasive tool to measure cortical oxygenation and address this gap. METHODS: This 12‑week, three‑arm randomized controlled trial (RCT) will enroll 186 older adults with MCI to systematically compare sequential Baduanjin exercise (BE) followed by cognitive training (CT), BE alone, and CT alone. The primary cognitive outcome is global cognitive function, assessed with the Montreal Cognitive Assessment (MoCA). The primary neurophysiological outcome is the resting‑state change in oxyhaemoglobin (oxy‑Hb) concentration in the prefrontal (PFC), premotor (PMC), and supplementary motor (SMA) cortices, measured by fNIRS. Secondary outcomes include specific cognitive domain performance, balance, activities of daily living (ADL), resting heart rate, and heart rate variability (HRV). All measures will be assessed at baseline, immediately post‑intervention (week 12), and at a 4‑week follow‑up (week 16). DISCUSSION: This study aims to evaluate the efficacy of sequential BE followed by CT in improving cognitive function in older adults with MCI. By quantifying fNIRS‑derived PFC‑PMC‑SMA activation and connectivity, the research will elucidate how BE optimizes the neurophysiological milieu to enhance the targeted effects of CT on cognition. The findings will provide evidence for personalized multimodal interventions and advance the understanding of non‑pharmacological MCI management. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR2500112116. Registered 10 November 2025.