Low-intensity Physical-cognitive Exercise and Cognitive Function

Effects of Low-intensity Exercise on Cognitive Function, Blood Biomarkers, and Metabolomic Alterations of Older Adults at Risk of Developing Dementia

This study aims to examine the effects of low-intensity, combined physical-cognitive exercise on cognitive function of older people with mild cognitive impairment (MCI) and identify the mechanisms by which this exercise protocol exerts cognitive function. Older adults with MCI will be recruited to either an exercise or a control group. Low-intensity, combined physical-cognitive exercise will be prescribed to the exercise group 3 times per week for 3 months while the control group will maintain their routine lifestyle. It is hypothesized that at the end of the trial, participants in the exercise group will demonstrate significant improvement in cognitive performance and circulating biomarkers compared to baseline and the control group.

Accumulating evidence suggests that dementia may be preventable, especially at an early stage. Mild cognitive impairment (MCI), a preclinical phase of dementia, is a potentially reversible condition as several individuals with MCI could revert to normal level of cognition. Exercise has shown promising evidence of neurocognitive protection, however, not all studies reported such benefits. Type and intensity of exercise are two main factors that have often been accounted for discrepancies in previous findings. Based on previous evidence, low-intensity and combined physical-cognitive exercise might give the best result for cognitive enhancement.

Thus, this study aims to examine the effects of low-intensity, combined physical-cognitive training on cognitive function of older people with MCI and identify the mechanisms by which this exercise protocol exerts cognitive function in individuals with MCI. A single-blinded, randomized controlled trial will be conducted. Older adults with MCI will be recruited to either an exercise or a control group. Low-intensity, combined physical-cognitive exercise will be prescribed to the exercise group 3 times per week for 3 months while the control group will maintain their routine lifestyle. Outcome measures will be assessed at baseline and after a 3-month exercise. The primary outcome measures will be cognitive performance (specific and global cognitive function) and plasma brain-derived neurotrophic factor (BDNF). The secondary outcomes will include physical performance (functional mobility and strength), interleukin 6 (IL-6), fibroblast growth factor 21 (FGF21), and metabolomic profiles. Intention-to-treat method will be applied for data analyses.

Inclusion Criteria:

• meeting the criteria for MCI (or mNCD) based on the recent DSM-V criteria
• comprehend instructions and able to comply with the study procedures
• not taking any medications for their cognition and not planning to start medications during the study trial

Exclusion Criteria:

• presence of medical condition(s) unsafe to exercise or affect cognition and mobility
• presence of depressive symptoms
• exercise regularly