Introduction
With the global population aging rapidly, the prevention of cognitive decline in older adults has become a top public health priority. While pharmacological treatments for dementia and cognitive impairment remain limited in efficacy, growing evidence from Randomized Controlled Trials (RCTs) and meta-analyses highlights structured exercise as a promising non-pharmacological approach. However, uncertainties remain regarding the most effective types of exercise, as well as the optimal frequency and duration for cognitive benefits.
Key Findings from Recent Network Meta-Analyses
Our recent network meta-analyses, synthesizing data from over 50 high-quality RCTs and nearly 4,000 older adults across multiple regions, reveal clear patterns of domain-specific cognitive benefits conferred by different exercise modalities:
- Resistance Training: Demonstrates the strongest effect on global cognitive function and inhibitory control. The optimal protocol involves twice-weekly sessions of 45 minutes over at least 12 weeks. This modality appears particularly beneficial for executive domains, likely linked to increased brain-derived neurotrophic factor (BDNF) and improved neural plasticity.
- Mind-Body Exercise (e.g., Tai Chi, Yoga): Most effective for improving task-switching ability and working memory, suggesting that physical-mental engagement can enhance cognitive flexibility and processing speed. Moderate frequency (≥3 times/week) and moderate session length (45–60 minutes) are recommended.
- Aerobic Exercise: Provides the greatest improvement in memory function, with the optimal effect achieved by longer-term interventions (≥21 weeks), twice per week, and sessions of at least 60 minutes.
- Multicomponent Exercise: Offers moderate benefits across cognitive domains, though generally less pronounced than single-modality protocols optimized for specific outcomes.
- HIIT: Limited but emerging evidence suggests possible benefits for executive function; more robust studies are needed.
These findings underscore the importance of individualized exercise prescriptions, tailored not only to the overall goal of cognitive maintenance but also to specific domains most relevant for the target population.
Practical Recommendations
- For older adults aiming to preserve overall cognitive health and executive function, resistance training should be prioritized.
- Those wishing to improve working memory and cognitive flexibility may benefit most from mind-body exercises.
- To enhance episodic and verbal memory, aerobic training is especially effective.
- Intervention frequency, session duration, and program length all matter: Moderate-to-high frequency (2–3 times/week), session duration of 45–60 minutes, and program lengths of 12–24 weeks yield the most pronounced cognitive gains.
Subgroup analyses further indicate that adults aged 65–75 and Asian populations may experience the greatest benefits, emphasizing the potential need for culturally tailored interventions.
Conclusion
Current evidence strongly supports the integration of structured exercise—especially resistance training, mind-body, and aerobic modalities—into dementia prevention and healthy aging strategies. Personalized, domain-specific exercise prescriptions, aligned with individual cognitive profiles and preferences, are essential for optimizing cognitive benefits in older adults.