Comparing 30 Versus 60 min Cognitively Loaded Physical Exercise on Cognitive Function and Physical Health in Community-Dwelling Older Adults With Mild Cognitive Impairment: A Double-Blind Randomized Controlled Trial.

Objectives: Mild cognitive impairment (MCI) is characterized by a mild decline in cognitive function and represents a risk stage for dementia in community-dwelling older adults. Exercise and dual-task training have been used to improve physical health, psychosocial health, and cognitive and learning functions in various subjects. However, the optimal time for these interventions has yet to be clearly identified. This study investigated the effects of cognitively loaded physical exercise (CLPE) on cognitive function and physical health in community-dwelling older adults with mild cognitive impairment and compared the differences according to exercise time.
Methods: Fifty-one community-dwelling aged 60 years or older with MCI were randomly assigned to 30-min CLPE (30CLPE, n = 17), 60-min CLPE (60CLPE, n = 17), and control (n = 17) groups. The CLPE program consisted of a twice-weekly exercise program for 8 weeks. During the exercise, a dual task was performed to assess cognitive load. The control group performed a typical exercise program at a dementia center during the same period. The Korean version of the Montreal Cognitive Assessment was used to evaluate cognitive function, and various physical health factors were assessed using the handgrip dynamometer and pinch gauge, Senior Fitness Test, dynamic and static balance abilities, and gait variables.
Results: After the intervention, both the 30CLPE and 60CLPE groups showed significant improvements in cognitive function, upper limb strength, senior fitness, balance, and gait (p < 0.05), while the control group showed no significant changes in any of the variables (p > 0.05). In between-group comparisons, both CLPE groups showed significantly improved cognitive and physical functions compared to the control group (p < 0.05). However, there was no significant difference between the 30 CLPE and 60 CLPE groups (p > 0.05).
Conclusions: The results of this study demonstrate that cognitively loaded physical exercise is effective in improving cognitive and physical function in individuals with MCI. Both the 30-min and 60-min sessions resulted in significant improvements, with no statistically significant differences observed between the two durations. This suggests that persistence and consistency of exercise may be more important than the duration of individual sessions.
Trial Registration: Clinical Trials.gov: KCT0009053.
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