Inclusion Criteria:

1. be between 60 and 90 years old;
2. scored < 9/12 on the SPPB;
3. scored >18/30 on the MoCA;
4. scored >9/42 on the PFFS;
5. lived in the community;
6. be able to ambulate up to four meters with or without assistive devices;
7. be able to provide written informed consent on their own behalf;
8. can understand verbal and written Cantonese and/or English.

Exclusion Criteria:

1. have magnetic resonance imaging (MRI) contraindications;
2. have aerobic exercise contraindications;
3. have transcranial magnetic stimulation contraindications;
4. be diagnosed with neurodegenerative conditions (i.e., dementia, Parkinson's, Alzheimer's disease, Amyotrophic lateral sclerosis, and stroke);
5. live in a nursing home or other care facilities/institutions;
6. bed taking fixed dose of medication or had been taking medications known to potentially affect cognitive and physical function (e.g., psychotropic medications), as identified through a review of their medication lists recorded in the health software. Medications were categorized by properties (e.g., antipsychotics, antidepressants, etc.) to inform eligibility decisions.
7. have a history indicative of carotid sinus sensitivity (i.e., falls due to loss of consciousness);
8. cancer and undergo radiation therapy.