Inclusion Criteria:
* Age \> 70 years
* 8 ≤ Insomnia severity index (ISI) ≤21
* 4m walking speed \<1 m/sec and \>0.44 m/sec
* Mild to moderate physical impairment (Short Physical Performance Battery score \< 10)
* Sedentary lifestyle (\< 150 min per week of moderate intensity physical activity) verified by CHAMPS questionnaire
* Willingness and ability to give informed consent
* Willingness to be randomized to the intervention groups
* Availability for participation through duration of study Exclusion Criteria (General)
* Failure to provide informed consent
* History or clinical manifestation of diabetes, cholelithiasis, liver or renal disease, cancer, or progressive, degenerative neurologic disease (e.g., Parkinson's Disease, multiple sclerosis, ALS)
* Abnormal laboratory markers (e.g., renal or liver abnormalities, elevated potassium levels, or hemoglobin and hematocrit below the lower limit of normal)
* Residence in a Skilled Nursing Facility (SNF); residence in an Assisted Living Facility (ALF) or independent housing is allowed
* Self-reported inability to walk one block
* Significant cognitive impairment, defined as a known diagnosis of dementia or a Mini-Mental Status Exam score \< 24
* Severe rheumatologic or orthopedic diseases (e.g., awaiting joint replacement, active inflammatory disease)
* Terminal illness with life expectancy less than 12 months, as determined by a physician
* Severe cardiac disease, including NYHA Class III or IV congestive heart failure, clinically significant aortic stenosis, history of cardiac arrest, use of a cardiac defibrillator, or uncontrolled angina
* Severe pulmonary disease, pneumonitis or interstitial lung disease
* Other significant co-morbid disease (e.g. renal failure on hemodialysis) or severe psychiatric disorder (e.g. bipolar, schizophrenia)
* Current use of antidepressant medications, antipsychotic agents, monoamine oxidase inhibitors, anticholinesterase inhibitors (i.e., Aricept)
* Refuses to reduce alcohol use to 3 or fewer alcoholic drinks per week during the study
* Planning to permanently leave the area in the next year
* Blood pressure readings \>180/100 at screening
* Participating in another clinical trial or has received an investigational product within 30 days prior to screening/enrollment.
Exclusion Criteria (AB-free kava-related)
* Regular use of any medications that contain acetaminophen
* Current use of any forms of kava and not willing to stop for a 2-week washout period - dietary supplements or beverages
* Current use of antidepressant medications and antipsychotic agents (including monoamine oxidase inhibitors), or anticholinesterase inhibitors (i.e., Aricept)
* Diagnosed with liver dysfunction or with previous liver diseases during the past five years
* Levels of ALT, AST, ALP or total bilirubin over 3xlimit of normal (ULN) range at prescreen
Temporary Exclusion Criteria
* Acute infection (urinary, respiratory, other) or hospitalization within 1 month
* Myocardial infarction, CABG, or valve replacement within past 6 months
* Pulmonary embolism or deep venous thrombosis within past 6 months
* Stroke, hip fracture, hip or knee replacement, or spinal surgery within past 4 months
* Receiving physical therapy for gait, balance, or other lower extremity training
