High Intensity Interval Training (HIIT) to Reduce Frailty and Enhance Resilience in Older Veterans

Cognitive status will be assessed using the VA - St. Louis University Mental Survey (VA-SLUMS) involving memory tests, shape recognition, and story recall. The survey scores range from 0-30, with a higher score representing greater cognitive capability. The investigators will also utilize the Cognivue to assess cognition. This is a combinatorial visual and reaction time test.

Serum cognitive marker: change in amyloid beta 42/40 ratio (a unitless measure derived from the ratio of serum amyloid-beta 42 in picograms per milliliter divided by serum amyloid-beta 40 in picograms per milliliter) from baseline to endpoint after 12 weeks.

Cognivue to assess cognition. This is a computer based combinatorial visual and reaction time test, which is scored 0 to 100.

Serum cognitive marker: plasma levels of phosphorylated tau (P-tau) in picograms per milliliter from baseline to endpoint after 12 weeks.

Serum cognitive marker: change in Brain Derived Neurotrophic Factor (BDNF) in picograms per milliliter from baseline to endpoint after 12 weeks.

Fatigue as assessed by the Brief Fatigue Inventory, which contains 9 self-rated questions with an aggregate score range of 0 to 90.

Objectively measure sleep quantity and stages using FITBIT Charge 5 actigraphy devices. These devices are worn on the wrist and sleep metrics, including total sleep time and time spent in light, deep, and REM sleep stages.

Sleep quality as assessed by Pittsburgh Sleep Quality Index (PSQI). The PSQI contains 19 self-rated questions that combined to form 7 component scores, each with a range of 0 to 3 points. These in turn are added to yield a global score with a range of 0 to 21 points.

Sleep chronotype as assessed by the Morningness/Eveningness survey, which contains 19 self-rated questions with an aggregate score range of 19 to 72.

Sleepiness as assessed by the Epworth Sleepiness Scale, which contains 8 self-rated questions with an aggregate score range of 0 to 24.

Insomnia as assessed by the Insomnia Severity Index, which contains 7 self-rated questions with an aggregate score range of 0 to 28.

Anxiety and depression as assessed by the Hospital Anxiety and Depression Scale (HADS), which contains 14 self-rated questions with an aggregate score range of 0 to 21.

Sleep disorders as assessed by the Holland Sleep Disorders Questionnaire, which contains 32 self-rated questions with an aggregate score range of 32 and 160.

The investigators will measure endurance in participants by asking participants to sit and rise repeated from a chair as many times in a 30 second time frame.

Frailty is a syndrome marked by greater susceptibility to adverse outcomes like falls and disability. The investigators will be using the Fried Frailty Phenotype that includes: 1) unexpected weight loss of 5% or more in the last year or BMI < 18.5; score 0 or 1 if positive, 2) grip strength with BMI dependent cut points for men and women; score 0 or 1 if positive, 3) gait speed with height and sex dependent cutoffs; score 0 or 1 if positive, 4) activity assessed by a survey of the frequency of mild/moderate/energetic physical activity; score of 0 or 1, the latter if positive for hardly ever or never engaging in moderate or energetic physical activity, and 5) endurance assessed by survey of bed rest during the day; score of 0 or 1, the latter if occurring every day or every week. The composite score is therefore 0 to 5.

Participants are asked to perform a timed walk of approximately 15 feet in length

Participants will receive a free weight (8lbs for men and 5lbs for women) and asked to perform total number of arm curls in 30 seconds while in a seated position.

Quality of life assessment is performed using the Quality of life, enjoyment, and satisfaction questionnaire - short form (Q-LES-Q-SF) survey instrument. The survey instrument scores from 0 to 70 with a greater score representing better quality of life.

Body composition will be measured using bioelectric impedance (BIA) - a technique where participants are asked to stand on the measurement device and hold on to two metal handles. A light - and non-detectable - current is then transmitted allowing for collection of body fat and lean mass in the subject. The assessment takes roughly 2-3 minutes.

Objectively measure activity using FITBIT Charge 5 actigraphy devices. These devices are worn on the wrist and capture total steps.

Chronic inflammation may be indicative of distress and lead to chronic diseases. The study will examine the change in C-reactive protein in picograms per milliliter in serum from baseline to endpoint at 12 weeks.

Chronic inflammation may be indicative of distress and lead to chronic diseases. The study will examine the change in interleukin-6 in picograms per milliliter in serum from baseline to endpoint at 12 weeks.

Chronic inflammation may be indicative of distress and lead to chronic diseases. The study will examine the change in interleukin-10 in picograms per milliliter in serum from baseline to endpoint at 12 weeks.

participants will be ask to perform a grip endurance assessment using an Eforto device. The device has a squeezable ball that measures force through changes in air pressure in response to squeezing. Participants are asked to attempt three maximal force tests at 5 seconds each, and then asked to maintain maximal grip for as long as they are able to hold.

Participants are measured for microsway (mm/s) while standing on a Biosway balance device. Participants will be asked to hold balance for 45 seconds while standing comfortably, standing with eyes close, standing with a narrow stance, and standing with a narrow stance with eyes closed.

Participants will be asked to wear a blood pressure cuff while a functional near infrared spectroscopy device measures flow flow in the lower arm. The cuff will be applied to restrict blood flow for 2 minutes, and then released to observe blood oxygenation recovery in the lower arm.

Participants will be asked to perform the Stroop color and word test. This test features three sections in which the participant will first read words written in black, then part two name the color of blocks, then the final part name the color of the written words.