Exercise and Sleep Study for Alzheimer's and Dementia

Inclusion Criteria: 1. Aged 55-80 years at the time of the screening visit 2. Able to ambulate safely and independently 3. Able to safely perform moderate-intensity exercise as per the Physical Activity Readiness Questionnaire (PAR-Q, a validated exercise readiness questionnaire) 4. Able to wear and use Fitbit wristwatch and/or the Elemind Neuromodulation headband and Lys devices 5. Able to operate a digital device like mobile phone or computer 6. Able and willing to provide venous blood samples 7. Able to understand and speak English (our AR-based MCI diagnosis tool does not yet have capacity for other languages) 8. Able to self-report a history of cognitive changes or impairment 9. Be cognitively able (including those with and without MCI) and willing to provide informed consent 10. Body weight \<400 pounds (\<181.4kg) in order to safely operate the NuStep T4r Recumbent Stepper stationary bicycle Exclusion Criteria: 1. Severe mobility limitations that prevent safe participation in moderate exercise protocols 2. Unstable or uncontrolled medical conditions (e.g., recent cardiovascular event (\<6 months), cerebrovascular accident or transient ischemic attack (\<6 months), active cancer, or uncontrolled diabetes) that pose safety concerns 3. Inability to complete intake screening procedures 4. Severe uncorrected hearing impairment-particularly if it precludes effective utilization of the Elemind Neuromodulation headband-and/or vision impairment that interferes with digital device usage or in-person exercise guidance 5. Determined to have Alzheimer's/dementia based on performance on the Quick Mild Cognitive Impairment (QMCI). 6. Inability or unwillingness to learn or engage with digital devices (e.g., smartphone, Fitbit, Elemind, or Lys), even with staff support 7. Regular pre-study engagement in ≥150 minutes of moderate-level and/or ≥75 minutes of vigorous-level exercise per week based on Fitbit data obtained during the initial seven-day onboarding screening period 8. Determined to have sufficient sleep, as defined by a sleep efficiency mean of ≥80%) based on Elemind Neuromodulation headband data obtained during the initial seven-day onboarding screening period 9. Current usage of disease-modifying therapy targeting amyloid (e.g., anti-amyloid monoclonal antibodies) or tau 10. Body weight ≥400 pounds (≥181.4kg), which would pose a safety risk during the operation of the NuStep recumbent stationary bicycle