Does Exercise Impact Cognitive Performance in Community-dwelling Older Adults with Mild Cognitive Impairment? A Systematic Review

Background: The prevalence of dementia and other cognitive disorders is expected to rise dramatically as the global population ages. Older adults who present with mild cognitive impairment (MCI) have an increased risk of developing more advanced dementia. However, there is currently no pharmacological treatment to slow the progression or reverse MCI. Thus, identifying effective non-pharmacological approaches to maintain or improve cognition is urgent. Aim: The purpose of this systematic review is to summarize the evidence surrounding the impact of exercise interventions on the cognitive performance levels of community-dwelling older adults who have MCI. Methods: Computerized database and ancestry search strategies located distinct intervention trials between 1990 and 2015. Results: Thirteen national and international studies with 1,171 participants were reviewed. Types of exercise intervention varied. The most common interventions were aerobic exercise, including walking, and Tai Chi. Most studies had an intervention duration of 10 weeks to 6 months, while only 4 studies lasted 12 months. Cognitive outcomes were mostly measured post intervention with no follow-up. Only one intervention was guided by heath behavior theory. Results indicated that physical exercise can benefit cognitive function among older adults who have MCI, including improvements in global cognition, executive function, memory, attention and processing speed. Physical exercise also can positively impact the physiology of the aging brain. However, the evidence surrounding the characteristics of effective physical exercise interventions in terms of exercise type, intensity, duration and frequency remains limited. Conclusion: Future rigorously designed large intervention studies with longer duration are needed to explore the effect of physical exercise programs on cognitive performance in older adults with MCI. Theory-based interventions with sex difference data and follow-up data are prefered. Moreover, clearly reported intervention design, participants' baseline activity level, compliance and acceptance and intervention fidelity control should be encouraged to facilitate the appropriate interperation of future studies. References