The following three-part proposal will focus on the effects of agility training as well as the relationship between agility ability and motor and cognitive function, and risk of falls in elderly adults with or without mild cognitive impairment (MCI).

Part I is a cross-sectional study design that will assess the level of agility in healthy young adults, healthy elderly adults, and elderly adults with MCI to determine the effect of aging and cognition decline on agility and the relations between agility, cognitive, and motor functions. Thirty participants will be screened for eligibility and recruited for each group (90 participants total). After collecting basic data, all participants will undergo cognitive and motor function tests, as well as an agility test. Cognitive function tests include tests of global cognition, working memory, mental set shifting, and selective attention. Motor function tests include tests of single and dual task walking, strength, power, balance, flexibility, and endurance. The agility test contains stop-and-go, change of direction, and spatial orientation components. Functional near-infrared spectroscopy (fNIRS) will be used to evaluate the brain activation during the agility test, cognitive tests, and single and dual task walking. Results from all tests will be used to determine the motor, cognitive, and other predictive factors associated with agility performance, and will be used in the design of the training program in Part II and III.

Part II and III are single-blinded randomized controlled trials that will explore the short and long-term effects of a multicomponent training and an agility training protocol on agility, motor, and cognitive function in elderly adults with and without MCI. Seventy-five elderly adults with MCI (Part II) and seventy-five healthy elderly (Part III) will be recruited. After screening for eligibility and collection of demographic data, participants will undergo a pretest assessment. In addition to the motor, cognitive, and agility tests used in Part I, information on history of falls, falls efficacy, and quality of life will be assessed for each participant. Brain activation will be assessed during the agility test, cognitive tests, and single and dual task walking assessments using fNIRS. Participants will be randomly allocated into one of three groups: the control group, the multicomponent training group, or the agility training group (n=25 in each group). Intervention will be executed at a frequency of 45 minutes per session, 2 times a week for 8 weeks. The control group will receive home-based health education guidelines. The multicomponent training group will engage in 3 to 4 exercises each training session comprising the influencing factors of agility, and the agility training group will engage in integrated task-specific training. A post-test will be conducted after the 8-week intervention, and 1-month, 6-month, and 12-month follow-ups will be conducted for elderly adults with MCI. The healthy elderly adults will be assessed after the intervention and at the 1-month follow-up after training.

Part 1:

Inclusion Criteria:

1. has a score of ≥ 24 on the Mini-Mental State Examination (MMSE)
2. able to walk independently for more than 30 meters without assistive aids
3. able to follow orders

Exclusion Criteria:

1. poorly-controlled or unstable systematic disease
2. has a history of central nervous system disease
3. currently taking antidepressants, anti-anxiety, or other psychiatric drugs that may affect blood flow in the brain
4. subjects with achromatopsia

Part 2:

Inclusion Criteria:

1. older than 65 years old
2. score of Mini-Mental State Examination (MMSE) ≥ 24 and score of Montreal Cognitive Assessment (MoCA) ≤ 26
3. able to walk independently for more than 30 meters without assistive aids
4. able to follow orders

Exclusion Criteria:

1. poorly controlled or unstable systematic disease
2. has a history of central nervous system disease
3. currently taking antidepressants, anti-anxiety, or other psychiatric drugs that may affect blood flow in the brain
4. has other medical conditions for which exercise is contraindicated
5. subjects with achromatopsia

Part 3:

Inclusion Criteria:

1. older than 65 years old
2. score of Mini-Mental State Examination (MMSE) ≥ 24
3. able to walk independently for more than 30 meters without assistive aids
4. able to follow orders

Exclusion Criteria:

1. poorly controlled or unstable systematic disease
2. has a history of central nervous system disease
3. currently taking antidepressants, anti-anxiety, or other psychiatric drugs that may affect blood flow in the brain
4. has other medical conditions for which exercise is contraindicated
5. subjects with achromatopsia