Graded Intensity Aerobic Exercise to Improve Cerebrovascular Function and Performance in Aged Veterans
Phase: NA
Conditions: Aging
Sponsor: VA Office of Research and Development

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Protocol 
1. Project Title 
Graded Intensity Aerobic Exercise to Improve Cerebrovascular Function and 
Performance in Aged Veterans 
(Short title: Graded Intensity in Aerobic Exercise) 
Principal Investigator:  Joe Nocera, PhD 
Co-Investigators:     Lisa Krishnamurthy, PhD 
Venkatagiri Krishnamurthy, PhD 
2. Abstract: 
This study will examine cerebrovascular function in older Veterans before and after a 
proven aerobic exercise intervention, allowing us to better understand the robust impact 
of exercise on brain function and health. Task-based fMRI and the resultant BOLD map 
is currently a dominant method of neurocognitive investigation, particularly related to 
documenting the beneficial changes demonstrated with rehabilitation. No single imaging 
technique can resolve the complexities of imaging neural plasticity in brain systems, 
therefore we propose a solution of combining imaging techniques and modeling the 
impact of perfusion and CVR on the BOLD response. We will model the hypothesized 
change in perfusion and CVR to the BOLD response following the intervention to 
quantify the percentage of variance both perfusion and CVR account for in the 
taskinduced BOLD signal. This will allow us to understand the degree to which change 
in perfusion and CVR impacts the well-documented beneficial change in task-induced 
BOLD following exercise. 
3. Background: 
The US Census Bureau reports that, of the 18.8 million Veterans of the U.S. armed 
forces, 9.3 million are age 65 or older. Another 7.7 million fall between the ages of 35 
and 65 years of age. Currently the median age for Veterans is around 64 years. As the 
Veteran population continues to age, the characteristics and comorbidities associated 
with aging will place a significant financial burden on the healthcare system. According 
to the Alzheimer’s Association, one in three of Veterans over the age of 65 will die with 
Alzheimer’s disease (AD) or a related dementia.1 Intertwined with aging-related 
pathologies are physiological changes in cerebrovascular function.2,3 In fact, recent 
epidemiological and clinicopathological data indicate considerable overlap between 
cerebrovascular dysfunction in aging and AD.4,5 While AD is an overt pathology, its time 
in a "sub-clinical" stage appears be years or even decades before the crossing of a 
diagnostic threshold.6 This sub-clinical stage spans a significant amount of time and 
provides a significant opportunity to initiate targeted interventions for limiting vascular 
dysfunction in older, at-risk Veterans. 

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It has been demonstrated that of all modifiable risk factors for AD, decreasing sedentary 
behavior is the most statistically significant and effective measure to counter the disease 
processes and associated cognitive decline in older adults.7 Nearly a quarter million 
cases of AD would be prevented in the US alone by improving the cardiovascular 
fitness profile in older adults.7 This staggering number is an exciting target not only for 
prevention but also as a means to better understand aging processes and underlying 
mechanisms malleable to exercise. Equally significant, this number probably 
underestimates the total impact of increasing cardiovascular fitness due to its effects on 
other risk factors in aging, including hypertension and obesity.8  
Two significant goals that are critical to VA RR&D and the aging Veteran population will 
be achieved with this study. First, this study will define the impact of aerobic exercise on 
cerebrovascular health in aging Veterans. Decreased vascular health because of aging, 
and particularly sedentary aging, fosters both cognitive and motor dysfunction9 and, as 
noted, has implications for neurodegenerative disease. We do know that older adults 
who are physically active have improved vascular health but we do not know the impact 
of an exercise intervention on cerebrovascular health. We will fill this gap by examining 
changes in basal cerebral perfusion and CVR in older Veterans following a proven 
cardiovascular fitness intervention. If our hypotheses of improved perfusion and CVR is 
supported it would inform current intervention strategies and would add important new 
information about the potential of exercise to improve brain health in aging. This would 
have immediate implications for aging Veterans at risk for neurodegenerative disease 
brought on by cerebrovascular dysfunction.  
Secondly, this study will advance the current state of literature regarding the beneficial 
impact of exercise on brain health and function. Research over the last few decades 
have driven the continual promotion of exercise as one of the most impactful 
interventions of central nervous system health and function.10-12 At the forefront of much 
of this research is the use of task-based fMRI BOLD to quantify beneficial changes in 
cortical function following aerobic exercise.13-15 While transformative, the true impact of 
this research is limited in scope until we can define the influence of cerebrovascular 
function on the well-documented beneficial change in BOLD response. Because the 
BOLD signal reflects the health and function of the cerebrovasculature,16,17 we believe 
the changes brought on by exercise are at least partially mediated by improved 
perfusion and CVR. Our statistical model in Aim 3 will allow us to quantify the impact of 
perfusion and CVR on the BOLD signal during task.  
Decreased Cerebral Perfusion in Aging  
The brain uses approximately 20% of available oxygen for normal function, making tight 
regulation of blood flow and oxygen delivery critical for survival.18 This high demand 
coupled with a lack of energy stores within the cortex necessitates that cerebral 
perfusion be constantly and consistently maintained. In a normal physiological state, 
total blood flow to the brain is remarkably constant, however, with advancing age basal 
perfusion declines by roughly 4 mL/min per year.19 It is presumed reactive oxygen 
species in the cerebrovasculature decreases NO bioavailability leading to the gradual 

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decline in endothelial function and subsequently perforating arteries, arterioles and 
capillaries. Ultimately, extracellular matrix components lose elasticity causing decreased 
vessel function and decreased blood flow.9,20  
Morphological studies demonstrate age-related degradation in perfusion throughout the 
intracranial vessels, however deceased cerebral perfusion is most notably amplified in 
the frontal cortex.2,19 While age-related decline in cerebral perfusion is not great enough 
to cause major ischemic injury, it results in hypoperfusion that prevents sufficient 
nutrients from reaching areas of high-metabolic demand such as the frontal cortex.21 
Our own data, presented below, demonstrate a decline in basal cerebral perfusion in 
the inferior frontal gyrus (IFG) and motor cortex in older adults when compared to 
younger adults. Of note, the decreased blood supply and inadequate delivery of 
nutrients is instrumental in age-related cognitive decline, specifically with 
cognitiveexecutive processes partially mediated by the frontal cortex.3 
Decreased Cerebrovascular Reactivity in Aging 
In addition to blood flow, the dynamic parameter of CVR has a critical role in 
cerebrovascular health and function. The cerebrovasculature must maintain blood flow 
within precise limits during rest, activity, disease or injury. In healthy individuals, 
perfusion is tightly regulated to meet the metabolic demands of the brain via 
vasoconstriction or vasodilation. Thus, the ability of cerebrovasculature to dilate in the 
face of increased demand is vital for cerebral function. However, the vasoreactive 
properties and vascular response to demand have repeatedly been demonstrated to 
degrade with age and neuropathology.9,22,23 To quantify the efficiency of  
cerebrovascular response, the degree of vasodilation in response to CO2, a vasoactive 
agent, is measured.24,25 Decreased responsiveness to CO2 is an accepted marker of 
CVR dysfunction and has been demonstrated to be sensitive to changes brought on by 
aging.2  
While the physiologic mechanisms that take place in the human cerebrovasculature 
resulting in neural decline are as yet unexplained, extensive work in the periphery 
demonstrates that age-related arterial stiffening and endothelia dysfunction play critical 
roles in the development of CVR dysfunction.9,20 Impairment of the oxidative stress 
response and dysfunctional inflammatory pathways feed a cascade of age-related CVR 
malfunction causing increased reactive oxygen species and reduced NO. Together the 
increase in reactive oxygen species levels and decreased NO suppresses the response 
of immune cells causing systemic vascular endothelia dysfunction.26,27,28 Behaviorally, 
decreased CVR has been observed in cognitive decline demonstrated in aging as well 
as dementia.23 
Impact of Exercise on Cerebrovascular Reactivity 
Aerobic exercise has consistently been associated with enhanced flow-mediated 
dilatation in the brachial artery of older adults.29 In the cortex, vasodilatation of the 
cerebrovascular in response to a CO2 challenge is associated with maximal aerobic 

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capacity in both young and old adults.30 Thus, in both the periphery and in the cortex, 
those with higher levels of cardiovascular fitness have improved CVR to stimulus. CVR 
was also shown to increases among stroke survivors after six months of aerobic 
training.31 Our own pilot data demonstrate marked decline in CVR with age. However, 
the degree of CVR decay is lessened in older adults that have high levels of 
selfreported aerobic activity.  
Link Between Cerebral Perfusion, CVR and Task-Based fMRI BOLD Response 
Seminal studies have continually demonstrated that sedentary individuals who undergo 
exercise intervention demonstrate BOLD activity that coincides with improvements in an 
array of tasks in both motor and cognitive domains.13-15 While the accessibility and ease 
of implementation have made BOLD a valuable tool, its interpretation is not 
straightforward.16 BOLD is a convoluted neurovascular signal that arises due to the 
interplay between changes in blood flow and metabolism in response to 
inhibitory/excitatory causing stimulus. Task-induced BOLD change (ΔBOLD) is 
measured relative to baseline BOLD signal, which means that baseline physiology 
(blood flow and perfusion) affects the task-induced ΔBOLD particularly in magnitude. 
We believe improvements in these baseline physiological factors are at least partially 
responsible for the well-documented, exercise-induced BOLD change. As noted, 
precise levels of blood flow depend on the health of the blood vessels that carry them. 
The blood carries important nutrient such as glucose and oxygen to support cellular 
energy demands, thus the amount of baseline perfusion is an indirect measure of tissue 
baseline metabolic demand. It should be noted that perfusion is a proxy for baseline 
neural activity, as increased neural activity results in increased demand for blood flow.32 
Further, the blood vessels must dilate in response to an increased demand for blood 
flow.32 CVR is an index of baseline vascular health that is necessary to support efficient 
cerebral perfusion. Thus, to isolate the issue of vascular ‘plumbing’ versus lower 
baseline neural activity, we would need to quantify both perfusion and CVR. Taken 
together, for a better interpretation of task-induced ΔBOLD, it is important to understand 
the relationship between baseline cerebral physiology (perfusion and CVR) and 
taskinduced ΔBOLD. To better understand the literature highlighting BOLD alterations 
following exercise, it is critical to quantify the impact of baseline physiologic measures, 
including perfusion and CVR on task-induced BOLD changes. We plan to accomplish 
this task by modeling the contributions of perfusion and CVR to ΔBOLD response both 
before and after the intervention. 
Mechanisms of Improved Cerebrovascular Function with Aerobic Exercise  
Arterial stiffening and cerebral endothelia dysfunction associated with aging results in 
decreased basal perfusion and CVR. These changes are known to contribute to 
agerelated declines in both cognitive and motor functions.3,9 Our preliminary work 
demonstrates that age-related vascular dysfunction is diminished in those that report 
regular engagement in aerobic exercise.  
Importantly, the mechanisms behind aerobic exercise and its influence on the peripheral 
vasculature have been extensively studied and provide strong support for the beneficial 

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role of exercise in cerebrovascular health and function. Aerobic exercise is associated 
with less large-artery stiffness and increased arterial compliance and elasticity.9 
Decreased arterial stiffness is a result of functional changes in vascular smooth muscle 
tone and structural changes to the atrial wall and extracellular matrix components.43  
This is critical as it supports the concept that aerobic exercise not only prevents arterial 
stiffness but also reverses any stiffening that occurs with age. Similarly, repeated 
studies demonstrate that aerobic exercise protects against the development of 
microvascular endothelia dysfunction.33,34 These studies, in both young and older 
aerobically-trained adults demonstrate greater NO bioavailability as the primary driver of 
a healthier endothelial profile. Both rodent and human studies support the use of 
aerobic exercise to lessen oxidative stress as well.35,36 Collectively, these systemic 
changes result in alteration to the vessel formation, which appears to be the mechanism 
at play for increased perfusion via increased cardiovascular fitness.  
In aging, there is increased risk of cerebrovascular dysfunction due to stiffening of the 
large arteries and impaired endothelia function. These physiological changes result in 
decreased perfusion and CVR. Much of the research done in the peripheral vasculature 
and early cross-section work provide evidence that cerebrovascular targets may be 
adaptable to an aerobic exercise intervention and serves as the guide for our 
mechanistic framework. A major gap in our understanding of exercise is how the 
cerebrovasculature responds to improved cardiovascular fitness in sedentary older 
adults. We have established an effective exercise intervention that has improved both 
motor and cognitive function with a concurrent and correlated change in BOLD signal 
during related tasks. These robust changes are hypothesized to be due, in part, to 
improved vascular function. As a next step, we propose to examine changes in cortical 
perfusion as well as changes in CVR following a proven aerobic exercise intervention. 
4. Specific Aims: 
The study will enroll 134 older, sedentary adults. Participants will be pseudorandomized 
to one of two 12-week intervention conditions: Aerobic Exercise or Stretching.  
Specific Aim 1: To determine the effect of a 12-week aerobic exercise intervention on 
changes in cerebral perfusion using arterial spin labeling in older Veterans. 
Hypothesis: Compared to a non-aerobic intervention Control group, the 
aerobicallytrained group will have increased basal perfusion in areas that demonstrate 
age-related decline and are malleable to aerobic exercise (inferior frontal and motor 
cortices). 
Specific Aim 2: To determine the effect of a 12-week aerobic exercise intervention on 
changes in cerebrovascular reactivity using a hypercapnic CO2 response test in older 
Veterans. 

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Hypothesis: Following the interventions, aerobically-trained older adults will have 
increased CVR to CO2 in the inferior frontal and motor cortices when compared to 
controls. 
Specific Aim 3: To quantify the impact of cerebrovascular perfusion and 
cerebrovascular reactivity on the BOLD response during task-based (cognitive 
executive and motor) fMRI. 
Hypothesis: Perfusion and CVR will account for a significant portion of variability in the 
BOLD response during task-based fMRI both before and after the intervention. 
Measures for Specific Aim 3. 
5. Design and Methods: 
Video and Telephone Consent Process 
To limit face-to-face interactions with participants, the study will be using Emory and VA 
approved video or audio communication to screen and consent. Some VA-approved 
virtual methods include Microsoft Teams Version 1.3+, Zoom 5.0 or greater, and Cisco 
WebEx version 40+. Recordings of the audio or visual communication will not be 
permitted.  If the participant meets initial eligibility criteria, we will mail or email through 
VA Outlook using encryption two unsigned copies of the ICF/HIPAA.   We will ensure the 
individual has enough time after receiving the document to read it before scheduled 
phone/video call.  Trained staff will perform consenting process including speaking with 
the individual to discuss the study and highlighting each section of the consent form, 
allowing the participant an opportunity to ask questions before providing consent, and 
giving the participant enough time to consider being in the study.  Study team will inform 
the individual that if they would like to take more time to consider the study, another 
telephone call can be scheduled.  If the individual would like to participate, the participant 
will sign and date the document and return it to study team via mail or via email to the VA 
Outlook email address. If the participant chooses to return the signed consent via email, 
they are required to send the consent as a reply to the original VA encrypted message 
sent by study staff. The study team will write a “Note to File” documenting everything 
about the interaction including:  
  
1. When and how the consent form was sent  
2. When the video/telephone call was made  
3. What was discussed during the call  
4. When the signed consent form was received  
5. When the signed consent form was signed by the person obtaining consent  
6. When a copy of the consent form signed by both subject and study team was given to 
the participant 
7. A description of why signature dates are different (if applicable) 
Once the study team receives the signed consent form, the person obtaining consent 
should sign the form and date it for the day it was signed. Study procedures will begin 

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once the signed copy is received.  A copy of the fully signed consent form will be given to 
the participant via mail or in person at the next scheduled visit. 
If consent is virtual, the option for DocuSign will be offered to the potential participant. A 
DocuSign envelope (email containing the links to study documents) with a reminder to 
NOT sign the documents prior to the scheduled contact time to review the documents 
with study staff and have questions answered. At the scheduled time the study team 
member consenting will contact the potential participant via VA and Emory-approved 
video or audio communication to guide the patient through the opening the DocuSign 
envelope and will review the documents contained.  
 
As per standard review of consent, the study team member will review the study 
consent. Trained staff will perform consenting process including speaking with the 
individual to discuss the study and highlighting each section of the consent form, 
allowing the participant an opportunity to ask questions before providing consent, and 
giving the participant enough time to consider being in the study. Study team will inform 
the individual that if they would like to take more time to consider the study, another 
telephone call can be scheduled. If the individual would like to participate, the study 
team member will guide the participant through completion of the fields in the study 
documents to sign them and finalize the documents. The study team member will then 
receive an email from DocuSign while still in the consent session with the participant 
and will verify it is completed correctly and accurately. The study team member will then 
guide the participant through downloading a copy of the signed consent documents to 
their local computer for their records. Thank them and conclude the call. The study 
team member will download a signed copy to the study folder on the VA network drive 
as the study record and a copy will be provided to Health Information Systems for 
upload to the medical record. The study team will document the consenting process in a 
“Research Consent Progress Note” in the VA medical record (CPRS or new system 
when we transition) everything about the interaction 
including: 
1. When and how the consent form was sent 
2. When the video/telephone call was made 
3. What was discussed during the call 
4. When consent was reviewed virtually and signed via DocuSign with a copy 
downloaded to their local computer for their records. 
 
Study procedures can begin once the DocuSign copy is received and documented 
Verbal Fluency 
1. Letter Verbal Fluency: Participants produce as many words (F, A, S, or P, R, W) as 
they can that begin with that letter in 60 seconds. Clinical findings are in line with 
numerous functional magnetic resonance imaging studies, demonstrating that letter 
verbal fluency is associated with extensive activation in the left frontal cortex. 
Further, age-related decline in letter fluency have been demonstrated. 

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2. Semantic Verbal Fluency: Participants produce as many words as they can that fit a 
particular category (animals or fruits/vegetables) in 60 seconds. This is generally 
considered a measure of a verbal component of executive function and has been 
demonstrated to decline with age. 
3. Switching Verbal Fluency: The switching condition evaluates the examinee's ability 
to generate exemplars while alternating between two different semantic categories 
(i.e. fruits and furniture) in 60 seconds. Switching requires the ability to engage in 
strategic search processes such as initiation, cognitive flexibility and mental set 
shifting. Because it is related to fronto-executive functioning, impaired performance 
is seen among patients with frontal lobe lesions and older adults.  
Response Inhibition 
1. Color-word Interference Test: Participants say the color in which another color word is 
printed in (e.g., for BLUE printed in red ink, the answer is ‘red’). This is a commonly 
used executive function task. Additionally, the interference effect, caused by difficulty 
inhibiting over-learned word reading, is often more pronounced in older adults. 
Working Memory  
1. Digit Span forward/backward: Participants must recall increasingly long strings of 
digits in order (forward) or reverse order (backwards) of presentation. Central 
executive component of working memory has been demonstrated to play a key role 
in digit backward span performance and age-related decline has been reported. 
2. Hopkins Verbal Learning Test: Assess verbal learning and memory (immediate 
recall, delayed recall, delayed recognition). 
3. Digit Symbol-Coding: a neuropsychological test sensitive to brain damage, 
dementia, age and depression. It consists of digit-symbol pairs followed by a list of 
digits. Under each digit the subject should write down the corresponding symbol as 
fast as possible. The number of correct symbols within the allowed time (e.g. 90 or 
120 sec) is measured. 
4. N-back task: Both the verbal and visual working memory tasks will be evaluated in 
the versions of the n-back task.  Versions of n-back tasks have been shown to be 
sensitive to working memory. During the n-back tasks, verbal or visual stimuli are 
shown one at a time using a laptop computer.  For each stimulus, participants click 
the left mouse button of the computer if the stimulus is a target and the right mouse 
button if the stimulus is a non-target. Targets are stimuli that occur n stimuli 
previously (i.e., n stimuli back).  For each task, 1-back, 2-back, and 3-back runs are 
given.  Each run has 100 stimulus presentations, with 20 targets and 80 non-targets. 
Stimuli are presented for 500 ms with inter-stimulus intervals of 3000 ms.  A 60 sec 
break occurs after the first 50 stimuli of each run.  Both accuracy and latency of 
response are recorded. Verbal and visual stimuli are as follows: (1) Verbal stimuli 

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are common, highly imageable English words 4 to 6 letters in length.  3 stimuli are 
chosen from each of 3 categories (animals, tools, vehicles).  Targets are trials in 
which an animal name is presented when an animal name is presented n stimuli 
back (e.g., in the following 3-back sequence, the target is in bold: “dog, horse, 
hammer, cat, car”).  (2) The visual task are 9 non-sense shapes.  Targets are any 
trial on which a shape is presented when the identical shape is presented n stimuli 
back.  
Non-Verbal Executive Function 
1. Trail Making Test A and B: Easily administered tests measure attention, visual 
searching, mental processing speed, and the ability to mentally control simultaneous 
stimulus patterns. 
Crystallized Word Knowledge 
1.  American National Adult Reading Test (ANART): reading test used to help assess          
intelligence. 
All cognitive testing will take place in the primary laboratory of the PI at the Atlanta VA 
Medical Center. All evaluations will be done by the PI or appropriate study staff. 
Additionally, to evaluate efficacy of interventions participants will self-report on:  
1. Mac-Q- 6 item questionnaire to asking participants to describe their ability to 
perform memory task as compared to when they were in high school.  
2. Behavior Rating Inventory of Executive Function (BRIEF)- Assesses self reported 
impairment of executive function task related to activities of daily living.  
3. Self-Efficacy for exercise scale - a 13-item instrument that measures self-efficacy 
barriers to exercise,  
4. Epworth Sleepiness Scale- self report used to determine the level of daytime 
sleepiness. 
5. Apathy Index (MAI)- 14 item self-report instrument that measures overall apathy 
and participants interest in new things.   
6. Pittsburgh Sleep Quality Index- 10 item questionnaire examining participants 
sleep habits over the past month.  
7. Patient Health Questionnaire (PHQ-9) – 9-item instrument that screens for signs 
and symptoms of depression. 
8. Pelvic Floor Distress Inventory Questionnaire (PFDI-20) – 20 item questionnaire 
that screens for bowel, bladder, or pelvic symptoms. 
Video Conferencing for Assessments 
To limit face-to-face interactions with participants, the study will be using Emory and VA-
approved video or audio communication to screen and consent. Some VA-approved 
virtual methods include Microsoft Teams Version 1.3+, Zoom 5.0 or greater, and Cisco 

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WebEx version 40+. Recordings of the audio or visual communication will be permitted 
as described previously to facilitate scoring of the assessment data in an off-line 
manner. During appointment scheduling, the participant will be asked if they have 
access to a computer with video, microphone, and speaker capabilities with access to 
high-speed internet that supports this level of communication. Once equipment access 
is confirmed the participant will be eligible to participate in tele-assessment, instructions 
for accessing the tele-assessment session will be sent via encrypted email through the 
VA outlook server. Any test that can be administered via video should be administered 
at this time. If an assessment cannot be accomplished remotely, it may be administered 
on the day of an in-person visit. 
Physical Function 
1. 400 Meter Walk: Participants will be asked to walk at their usual pace, without 
over-exerting. They can stop for up to 1 min for fatigue or other symptoms.  A 
time limit of 15 minutes to perform the test has been established based on the 
following considerations. First, individuals who complete the walk in >15 minutes 
have an extremely slow pace (<0.44 m/sec), which would make their walking 
capacity of little utility in daily life. Second, selecting a higher cut-point, such as 
30 or 60 minutes makes the objective assessment impractical and does not add 
to the clinical significance of the outcome. Participants will be allowed to use a 
cane, but not a walker, to complete the 400m walk. Procedurally, we will first 
request that participants attempt the walk without the use of a cane. Those who 
feel unsafe will be allowed to attempt the walk with their cane.  
2. Walking and Walking While Talking: Participants will be asked to walk across an 
electronic walkway which captures walking speed and foot placement in a quiet 
well-lit hallway wearing comfortable footwear. Start and stop points 10 meters 
apart will be marked by lines on the floor and include 3 feet from the walkway 
edge for initial acceleration and terminal deceleration. Eight walking trials will be 
randomly conducted; 4 singles tasks walking only trials and 4 dual task walking 
while talking trials. For the walking while talking trials participants will be asked to 
recite alternating letters of the alphabet. The order of the initial letter will 
randomly vary between “A” and “B” to minimize practice effects and/or count 
backwards by 3’s.37 
3. Short Physical Performance Battery (SPPB): The SPPB is based on a timed 
short distance walk, repeated chair stands and a balance test (as described by 
Guralnik et al.38). The battery will be administered by a trained and certified 
examiner. 
4. The Activities-specific Balance Confidence (ABC) Scale: Indicates self-report of 
participants’ level of confidence in doing daily activity without losing their balance 
or becoming unsteady. Self-Report Function Questionnaire. We will use a 

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modified version of the disability instrument that was used in LIFE-P, now called 
the Pepper Assessment Tool for Disability (PAT-D)44.  The questionnaire 
inquiries about perceived difficulties in general activities of daily living during the 
last month. For each item, the response categories include: 1) no difficulty, 2) a 
little difficulty, 3) some difficulty, 4) a lot of difficulty, or 5) unable to do.  Answers 
are averaged across the items, in order to better assess the overall perceived 
disability burden by a person. The questionnaire consists of 5 subscales: 
mobility, transferring, upper extremity, instrumental and basic ADLs. In addition 
to being a valid measure, the disability questionnaire has been shown to be 
responsive to change in previous exercise intervention studies among various 
disease populations 45.  
5. Sit and Reach Test: This test assesses the flexibility of the lower back and 
hamstrings. Participants will sit on the floor and reach as far they can towards 
their toes. The test will be performed three times while measuring the distance 
reached.  
6. Functional Reach Test: This test will assess participants’ balance and functional 
mobility by having them stand perpendicular to a wall and reach out as far as 
possible. 
7. Leg Press: An assessment of bilateral leg movement function will be completed 
using the Keiser Leg press. 
8. To confirm the cardiovascular effect of the aerobic training participants will also 
perform a Maximal Treadmill Exercise Test or a Submaximal Treadmill Exercise 
Test.   
Submaximal Treadmill Exercise Test: (For participants unable to complete a maximal test or 
if maximal testing is not indicated…) Submaximal exercise testing will be performed using an 
exercise protocol validated for this purpose (e.g., Naughton, modified Bruce, or similar). For 
graded protocols where participants progress through a series of stages in which speed, incline, 
or both are increased in a stepwise manner, the progression will be such that it allows the 
participant to adapt to a specific workload before advancing onto a more difficult stage. 
Termination of the test occurs if the participant requests to stop, the submaximal threshold is 
reached, other symptoms prohibit further exercise, or there is an absolute indication for 
termination of exercise testing. 
 
Maximal Treadmill Exercise Test: Unless contraindicated, participants will undergo maximal 
exercise testing using an exercise protocol validated for this purpose (e.g., Bruce, Balke, or 
similar, or using a ramp protocol). Participants will progress through a gradual increase in work 
rate based on the specific protocol being used until they either become fatigued and decide to 
stop, develop other symptoms that prohibit further exercise (e.g., musculoskeletal pain), or there 
is an absolute indication for termination of exercise testing. Vital signs, including blood pressure 

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and heart rate, will be recorded at regular intervals throughout the test, and participants will be 
monitored with continuous electrocardiography. Participants may also be asked to report their 
rate of perceived exertion (RPE) at various points during the test. After testing, participants will 
be monitored until their heart rate and perceived exertion have normalized. A registered nurse 
(RN) or exercise physiologist (EP) will be present for the test duration.  
 
9. Electronic Activity Data: Electronic activity data will be generated by Apple 
Watches functioning in two possible modes. Each mode has unique 
requirements for data security. The Watch will collect the participants’ daily total 
activity level. 
Stand-alone: Some Apple Watches loaned to participants will be paired with VA 
furnished iPhones. When not loaned out to participants, these iPhones will 
remain at the VA in a locked and secure environment (12C-173b). Because the 
watches will be functioning at a remote location, they will be unable to sync the 
data they generate to an iPhone or a network cloud. Instead, our team has 
written code to preserve this data in formatted files on the watch until the watch 
is returned to our possession. The data stored on passcode protected Apple 
Watches is secured with AES-256 encryption. 
Once the watch is returned to the VA, it will be synced to the VA-issued iPhone.  
(iCloud backup will be disabled for apps handling Apple Watch generated data.) 
The data transferred will be devoid of participant identifiers except participant 
study ID, year of birth, timestamps, and Apple Watch device identifiers. It should 
be noted that although the timestamps contain dates, these dates are not directly 
related to significant life events (e.g. birth, death, hospital admission) but rather 
are continuously catalogued while the watches are on and not charging. Also, 
Apple Watch device identifiers are not perpetually unique to a participant 
because these watches are VA property and will be worn by numerous 
participants over time. Regardless, data stored on passcode-protected watches 
and phones will remain AES 256-bit encrypted. 
Once data files are located on a VA iPhone, they will be backed up to a study 
controlled Apple iTunes account that is linked to a study-provided Apple User 
identification (UID) and transferred to a disk-encrypted, password-protected VA 
laptop. (Local iTunes encryption is optional by default but will be enabled for our 
purposes.) 
Deployed with VA-issued iPhone: Some Apple Watches will be loaned to 
participants along with the iPhones to which they are paired. This mode is 
preferable to the Stand-alone mode; however, Stand-alone mode may be 
necessary if access to VA-issued iPhones is limited. Most data handling 

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procedures and precautions used for Stand-alone mode apply to this use-case 
as well, including use of participant Study ID, AES 256-bit encryption, and 
disabled iCloud backup. One exception is that data generated by the Apple 
Watch will be synced directly to the paired VA-issued iPhone (i.e. - our code 
writing files to the Apple Watch will not be used). The iPhones loaned to 
participants will not have data plans. Therefore, unless participants have Wi-Fi 
access, data will be retrieved from the iPhones as described for Stand-alone 
mode after the phones are returned to the study team (i.e. study-controlled 
iTunes encrypted backup, and ultimately, transfer to a VA password-protected 
computer). If participants have Wi-Fi access, study data will be transferred to a 
remote server (hosted by Emory University in a secure data center under a VA 
Data Usage Agreement) via SSL encrypted connections. Terms specified in the 
handling of research data in the Data Usage Agreement will apply.  
To increase data security, de-identified user data will be encrypted using Apple’s 
Secure Enclave coprocessor embedded in Apple’s A9 series processors (in the 
iPhone SE and Apple Watch). A FIPS-140-2 FISMA High environment, the 
Secure Enclave runs the L4 microkernel which is signed by an ephemeral key 
and cnonce entangled to the unique ID (UID) of the user with antireplay initiated 
at login. Antireplay revokes all data back transformation of encrypted data 
without express sign-on through direct passcode authentication. This means that 
all data is encrypted throughout transmission until authenticated by the UID on 
an iOS device. The encryption scheme uses a dedicated AES-256-XNT engine. 
No software or firmware can read this data directly. Only after decryption by the 
silicon based cryptographic engine using the UID key can the data be accessed, 
and this is further restricted to devices sharing a group id (GID). This can only be 
completed on another iOS device that has the UID (which is controlled by the 
study coordinator) and the Secure Enclave decryption engine on a device with at 
least an A7 series encryption coprocessor. Apple synchronizes this encrypted, 
de-identified data on its secure Health environment located on cloud services. 
These data cannot be decrypted or read by any party that does not have access 
to the UID, generated at the outset of the study and resides with the study staff. 
Only study staff can read files from the Health environment due to this 
encryption. Even if the physical chips are removed from the device to access the 
data, the device UID that created would maintain encryption of the data 
rendering the files inaccessible. Apple’s cryptographic architecture received NIST 
validation as FIPS-140-2 validated with Certificate #3148 (3/8/2018 - 3/9/2023). 
For all modes, filenames contain dates and times indicating when the files were 
created for transmission/export. These dates/times do not necessarily reflect 
date and times that the data were generated. 
Motor Testing 
1. Purdue Peg Board Task: The Purdue Pegboard measures unimanual motor 
dexterity. The test consists of two parts: 1) placing pins in a column of holes and 

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2) an assembly task using three components (pin, washer, collar). The 
participant is asked to place as many items as possible in 30 or 60 seconds, 
respectively.  
2. Nine Hole Peg Board Task: A standard dexterity assessment, this task asks 
participants to place and remove pegs on a nine-hole pegboard as quickly as 
possible. 
3. Pinch and Grip Strength: FDI and hand strength will be assessed using standard 
dynamometer (JAMAR) squeeze tests. 
4. Coin rotation task: Another dexterity assessment, this task asks participants to 
rotate a coin (U.S. quarter) as quickly as possible for 20 rotations. 
5. Halstead finger tapping: The Halstead finger tapping test is a standard test for 
testing psychomotor speed.  The participant is asked to press a lever attached to 
a counter as many times as possible in 10 second trials. 
MRI  
Structural Imaging: High-resolution T1-weighted and T2-weighted structural imaging will 
be obtained to assess Tissue Integrity Gradation via T2w T1w Ratio (TIGR) and will also 
serve as an anatomical reference for functional data. We will also collect Diffusion 
Weighted Images (DWI) to assess white matter integrity. During this time participants 
are given the option to view a movie to alleviate potential boredom.  
Metabolic Imaging: Cerebral Blood Flow will be assessed with MRI scans that separate 
pure blood signal from surrounding tissue (e.g. pCASL or VSASL). If arterial transit time 
is a factor based on the imaging sequence, we will remove this confound by either using 
longer post-labeling delays or measuring multiple post-labeling delays. For a few minutes 
of scanning, we will ask participants to breath via a mask air richer in CO2 than normal 
atmospheric air (5-8%).  CO2 will be administered by study staff. The CO2 reactivity 
procedures are tolerated by normal, elderly subjects and patients with neurological 
diseases such as history of strokes and have been performed numerous times in our 
imaging center without complications. 
Functional Imaging: Integrity of functional brain networks will be assessed while the 
participant is lying still inside the scanner, and Blood Oxygen Level Dependent (BOLD) 
fMRI signals are collected. Alternatively, the participant may be asked to perform either a 
language task or motor task while BOLD fMRI data is collected, depending on the 
question of interest. 
Magnetic Resonance Spectroscopy: Magnetic resonance spectroscopy will be performed 
on selected large (e.g. 4-27 mL) voxels to estimate quantities of various neurochemicals. 
γ-aminobutyric acid (GABA) and glutamate are the primary neurochemicals of interest, 
though other substances (e.g., N-acetylaspartate, creatine) may also be measured. 

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Regions of interest include, but are not limited to, the DMN (medial and lateral structures), 
motor cortex (M1), inferior frontal gyrus, and fusiform gyrus. 
No exogenous contrast agent will be used during any of the MRI and MRS protocols. 
FMRI Tasks 
For the verbal fluency task in the scanner, participants will see different categories at 
the center of a video screen while in the scanner. The participant’s task will be to 
generate different exemplars of the respective category (semantic) or as many words 
that begin with a particular letter (phonemic). The fMRI fluency task will consist of two 
blocked conditions of category or phonemic generation, which will alternate with a 
control condition (reading the word “rest” aloud). A baseline condition will be used to 
control for activity associated with (a) basic visual processing, (b) articulation and, (c) 
hearing of the subject's own voice. A total of 4 blocks for each condition will be collected 
(i.e., 40 trials for category and phonemic fluency).  
For the verbal working memory task, both memory and control trials will be presented in 
a pseudorandom order across five runs, each containing 14 trials. This will produce 35 
memory trials and 35 control trials over the course of the experiment. For a memory 
trial, the first slide will depict a single lexical target. Participants will be instructed to read 
and remember this “target word” with the knowledge that sometime later they will be 
shown a second word, referred to here as the “decision word”. Upon seeing the decision 
word, participants will initiate a button press indicating whether the target and decision 
words are semantically related. The time in-between presentation of the target and 
decision words will be filled with additional slides, referred to here as “distractor slides”. 
Each distractor slide will present two words. Participants will be asked to make a 
semantic relatedness judgment for each of these distractor word pairs. A single memory 
trial is depicted in the diagram below. The timing parameters will be identical for both 
the memory and control trials. Specifically, slides 1-4 will present for 2 seconds each, 
and slide 5 will be shown for 4 seconds. A 10-second blank screen inter-trial interval will 
be used to allow hemodynamic response recovery. 
Diagram of the experimental task, showing a single memory trial and a single control 
trial. Each trial will last 12 seconds for both task conditions (control & memory) and will 
be separated from the subsequent trial by a 10-second blank screen. Color-coding 
indicates the phases delineated for the functional task activation analysis. 

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The fMRI acquisition for semantic will follow protocols currently utilized in the 
investigator’s laboratory and therefore will employ a sparse-temporal sampling design in 
which the response is assessed in the scanner during an off-phase, and the 
hemodynamic response is acquired after a short time delay; thereby movement artifacts 
due to the articulation process are avoided. Since the working memory task involves no 
overt speech, a continuous sampling acquisition will be used to allow for temporal 
resolution of the different phases of the working memory task. A T2*-weighted FastField 
Echo, Echo-Planer-Imaging (FFE-EPI) sequence utilizing a parallel imaging technique 
will be used. Prior to the first scan, a training session outside of the scanner will be 
performed to familiarize the participants with experimental tasks. Participants will be 
scanned prior to and following the 12-week intervention. Additionally, for fluency both 
semantic and phonemic stimulus presentation will be different but equalized for difficulty 
from pre to post.  
The MRI/FMRI will be conducted at Emory University Hospital (EUH). EUH houses a 3 
T Siemens Trio scanner with the total imaging matrix (TIM) suite.  The scanner is 
equipped with a 32-channel Siemens head coil, which allows for rapid acquisition of 
high-resolution functional images (e.g., 2 X 2 X 2 mm voxels with a whole brain 
acquisition every second). It has the latest Siemens VB17 software and has a number 
of advanced Siemens product sequences including Blood Oxygenation Level 
Dependent (BOLD) imaging and in-line analysis suite with 3D PACE real time motion 
correction.   
Blood Draws and Biomarker Evaluation 
Whole blood will be collected, by a certified phlebotomist, through one venous port 
venipuncture or peripheral venous line into standard plasma tubes or serum separator 
tubes (~40 ml per visit). Following collection, tubes will be transferred in accordance 
with blood borne pathogens training standards to the Molecular Core facility of the 
Atlanta VAHCS. Serum and plasma aliquots will be analyzed for biomarkers (e.g., 
BDNF) by ELISA, western immunoblotting, and other standard molecular biology 
assays. 

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Saliva will be collected at study assessment visits in a 15mL sterilized tube; roughly 
3mL. Once collected, saliva will be immediately placed on ice and stored at -80 degrees 
until subsequent analysis. 
The procedure below describes the blood and saliva collection timeline during the 12-
week intervention period for both intervention groups:  
Week 1: Taken immediately prior to exercise, immediately post, 15 min post, 30 
min post.  
Week 6: Taken immediately prior to exercise, immediately post, 15 min post, 30 
min post.  
Week 12: Taken immediately prior to exercise, immediately post, 15 min post, 30 
min post.    
All blood draws will be conducted at the Atlanta VA Health Care System. Tubes will be 
coded and thus have no identifiable patient information. It is expected that all blood 
sample processing and storing will be conducted at the Atlanta VAHCS in the Molecular 
Core facility. However, in the event that equipment or other resources are needed for 
completing sample analysis, samples will be analyzed at Emory University (5th Floor, 
Emory Eye Center, Clinic Building B, 1365-B Clifton Road, Atlanta, GA). Sample labels 
will be de-identified by having only Subject #, Visit #, Draw #. The master code list will 
be maintained in a locked file cabinet in the Atlanta VAHCS office of the PI or 
Coinvestigator. Deidentified sample remainders will be kept at the Atlanta VA Core 
facility or, if needed, the Emory facility, while the study remains open. 
Finger prick blood measurements 
Similar to a glucose meter, a hematocrit (Hct) meter requires a very small droplet of 
blood to measure hemoglobin and Hct using a photometer with broad spectrum. We will 
use an analyzer called the HemoPoint H2 from StanBio Laboratory. This device is a 
palm-sized blood hematocrit test meter that quickly measures hemoglobin and Hct from 
a small blood sampling (0.3µl). Measurements are completed in 30 sec, so this 
measurement can be completed rapidly and repeatedly within a single session. Prior to 
each puncture, we will cleanse the target skin site with an alcohol swab. We will use a 
28 or 30G lancet to draw a droplet of blood into a measurement strip for each 
measurement. After recording the data, we will discard the lancet and the lactate strip 
into a Sharps container for safe disposal. We will apply direct pressure to the site of 
puncture with a sterile gauze pad. The puncture procedure will attempt to minimize pain 
and discomfort for the participants. The Hct measures will be utilized along with MRI-
based pCASL measures to accurately quantify the subject’s CBF. 
 
Interventions 
Aerobic Exercise Group: For this arm of intervention, randomized participants will attend 
spin exercise training sessions demonstrated to facilitate physiological changes. For the 

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aerobic exercise component of this group, participants will follow the guidelines 
provided by the American College of Sports Medicine for optimizing cardiovascular 
fitness. Thus, participants will exercise 3 times a week on a stationary ergometer. 
Exercise intensity will begin at low levels (50% of maximal heart rate reserve) calculated 
utilizing the Karvonen method. Briefly, target exercise HR is calculated by subtracting 
the persons age from 220.  Resting heart rate is then subtracted from this number. The 
answer is then multiplied by the target percent (50% for example) and the product is 
added back to resting heart rate to provide the target exercise session heart rate. 
Intensity will be increased by 5% every week (as tolerated by the participant) to a 
maximum of 90% of maximal heart rate. Exercise time will progress from an initial 25 
minutes per session to a maximum of 60 minutes by increasing 5 minutes each week. 
Each session will be monitored by a certified CPR and fitness specialist. Further, the 
intervention site is located in the Atlanta VA Health Care System and portable 
defibrillators are available at the intervention site.  
Interval Exercise Group: For 12-weeks participants will engage in progressive whole 
body stretching, toning and balance exercises designed for individuals 65 years and 
older. Participants will meet for the same total duration time as the aerobic exercise 
group. Heart rate will be monitored to ensure participants maintain exercise levels below 
aerobic training zone. 
Remote Exercise Monitoring: As an alternative, participants that are uncomfortable with 
receiving face-to-face training within the hospital will be given the option to continue their 
exercise intervention visits remotely. For participants that have been randomly assigned 
to the ‘spin’ exercise training program, will be provided a stationary cycle ergometer that 
has been sanitized properly to use during the 12-week period. All subjects will be 
monitored and trained through VA and Emory approved remote access sites. 
Control Group: A random subset of participants will be in a 12-week wait-list control. 
These participants will undergo the same scanning procedures as described above 
without cognitive or physical function testing. After 12-weeks these participants will 
come in and undergo the pre-assessment, 12-week exercise intervention and post 
assessment as described above.  
Exercise Lab Space  
The exercise classes and cognitive training will be held in the Movement Studies 
Laboratory in the Atlanta VA Rehab R&D Center. The Movement Studies Laboratory is 
a 41 X 34 ft. work out area that will serve as the venue for the group exercise. Because 
the lab space is housed in the Atlanta VAHCS, emergency procedures are done in 
accordance with emergency preparedness plans. A phone is located in the facility which 
can be used to contact emergency services (911) in the event of a medical emergency. 
CPR and the AED will be utilized if needed until Emergency Services assumes 
responsibility. All staff are certified in basic life support and first aid and the facility 
houses AED devices. A second location for exercise classes is the Geriatric Research 

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Education and Clinical Center (the GRECC), an offsite Atlanta VA affiliate facility, that 
follows the same rules and regulations as the rest of the Atlanta VA Healthcare System. 
Risks/Discomforts 
Cognitive Testing 
Patients may experience some frustration if they have trouble with cognitive testing.  
Researchers will be trained on how to handle frustration by taking breaks, allowing 
patients to express frustration, and offering encouragement.  As noted above, we will 
also include items that the participants can answer correctly to minimize frustration.  In 
the vast majority of patients, these techniques are adequate to deal with frustrations.   
Magnetic Resonance Imaging (MRI) 
More than 150 million diagnostic magnetic resonance studies have been performed 
worldwide.  The vast majority of these procedures were completed with no sign of 
patient injury.39 There is a high degree of patient safety with an fMRI because of the 
miniscule value of magnetic susceptibility and lack of ferromagnetic components of 
human tissue.  Studies have ranged in magnetic field intensities from 1.5 to 8T.  No 
negative cardiac, physiological, or cognitive effects were noted.40 Therefore, long-term 
effects on human health from magnetic resonance imaging are unlikely.  Those at risk 
for injury include those with indwelling ferromagnetic material (e.g. foreign object in eye, 
surgical implant) or an implanted bioengineering device (e.g. pacemaker, infusion 
pump), due to the possible interaction with a magnetic field.  Subjects identified as at 
risk from the screening checklist will be excluded from the study. 
Another potential hazardous effect is related to the high-level of noise produced by the 
machinery during imaging.  Unprotected, patients can experience hearing loss.  For this 
reason, individuals will be given foam earplugs to wear to minimize this risk.   
Additionally, some individuals are perceptible to experiencing distress during the fMRI 
process.  The small, closed-in space may trigger anxiety.  Participants will be screened 
for claustrophobia, generalized anxiety disorder, post-traumatic stress disorder, or 
obsessive-compulsive disorder.   
Further, persons who are pregnant (or could be pregnant) or those with a seizure 
disorder should not undergo magnetic resonance imaging and will be excluded.   
The reported potential side effects of the CO2 mask may include a feeling of dizziness, 
faintness, or anxiety during CO2 inhalation. 
Subjects may have early stages of disease, not previously diagnosed, detected through 
the use of MRI. A trained neuroradiologist is available to the investigators to evaluate 
the findings and determine if there is pathology present or a normal variant should the 
investigators suspect that the imaging shows abnormalities.  If pathology is present or 
suspected, subjects will be counseled about what the findings are and what should be 
the next steps for clarification of ambiguous findings or seeking help with pathological 

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findings.  This is not a risk in the conventional sense of physical harm or disease but 
does pose a potential psychological risk to the patient. 
Blood Draw 
The risks of drawing blood from a vein include discomfort at the site of injection; 
possible bruising and swelling around the injection site; rarely an infection; and, 
uncommonly fainting from the procedure.  A trained phlebotomist will collect all blood 
samples following standard protocol. 
Physical function and Exercise Intervention 
While the risk of a cardiac emergency is increased when a person is exercising, these 
events are rare and usually occur during high-intensity activities. The cardiovascular 
benefits of exercise have been consistently shown to outweigh the acute cardiovascular 
risk during the act of exercising. Moreover, a person beginning a moderately intense 
exercise program is actually at a lower overall risk of sudden death than their sedentary 
peer.  Neither an ECG nor a stress electrocardiogram will be included in the screening 
process due to the lack of evidence to support their usage in detecting those who will 
have an adverse exercise outcome. 
Some participants will experience exercise-related injuries and possibly muscle 
soreness and fatigue as a result of the testing and the intervention. There is a small risk 
for loss of balance and injury from a fall while walking and during balance 
measurements.  However, walking and balance measurements will only be a few 
minutes at a time, and research personnel will be with the participant at all times. Most 
injuries will be self-limited, though it is possible for permanent injuries to occur, including 
broken bones or joint problems. There are minor risks of musculoskeletal problems 
associated with the performance evaluation measures of the study.  
The potential risks of loss of confidentiality will be minimized through assigning all data 
collection instruments a unique code without individual identifying information. All 
HIPAA regulations pertaining to protection of participants and eliminating identification 
will be followed.  
 
Potential Benefits 
There are substantial potential benefits of participation in this study.  All participants 
may benefit from the pre-intervention evaluation, which may detect unknown or 
inadequately treated medical problems. Potential benefits for adults who exercise 
include: 
• 
improvement of physiologic indicators of health (e.g., balance, blood pressure); 
• 
full or partial elimination of impairments in ability to do daily activities; 
• 
improvement in mental and/or social health status; 
• 
reduction of risk of falls and fall-related injuries; reduction in risk of mortality; and 
reduction in medical care costs. 

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Potential benefits for adults who participate in the exercise testing include: 
• 
improved awareness of their cardiovascular fitness level; 
• 
greater confidence in the knowledge of their cardiovascular fitness level; 
• 
greater knowledge of their fitness changes and the relationship between those 
measures and their ADLs. 
• 
improvement in mental and/or social health status; 
• 
reduction of risk of falls and fall-related injuries; 
• 
reduction in risk of mortality; and 
• 
reduction in medical care costs 
6. Participant selection: 
The study will enroll sedentary older adults and young adults as a comparison group for 
the MRI scans. Older adult participants will be pseudo-randomized to one of three 
12week intervention conditions: Aerobic Exercise, Interval Exercise, or Control. The pre 
and post evaluations will be conducted over 2 days during a 1-week period. Each day 
will last no more than 2 hours. The investigators expect a dropout rate of anywhere from 
15-20% of participants. To ensure completion of study by 108 participants, as many as 
134 subjects may be enrolled.  
Inclusion/Exclusion Criteria  
Prior to beginning any portion of this study, we must receive a physician, physician 
assistant, or nurse practitioner’s written medical approval for participation in the fitness 
assessment and/or exercise intervention. We will provide a letter to sign explaining the 
study protocol. The key inclusion criteria and final participant pool will consist of right-
handed English-speaking individuals ages 18 to 80. Older participants will be sedentary 
as defined by <40 min/week of aerobic exercise. Additionally, participants will be non-
demented and will have no cognitive-executive function deficit (MoCA ≥ 26). Further, 
those with severe diabetes requiring insulin will also be excluded. However, those with 
less severe, controlled diabetes that meet our physical and cognitive function inclusion 
criteria will be allowed to participant. Participants must not have conditions incompatible 
with MRI (including but not limited to, ferrous metal implants, cardiac pacemakers or 
similar devices, claustrophobia, morbid obesity). Potential participants with major 
psychiatric disorder (including but not limited to psychosis, major depression, bipolar 
disorder) by history will be excluded. 
Recruitment 
Individuals will be recruited from the Atlanta VA Rehab R&D Subject Registry 
(IRB00000159) based on the inclusion and exclusion criteria. The Subject Registry 
study staff will query the database of all patients meeting the inclusion and exclusion 
criteria who have consented to be contacted for research purposes and will print out 
their contact information. The Principal Investigator, or his research colleagues, will 
contact these individuals and will summarize the study procedures. If the potential 
participant is interested, we will mail them a copy of the informed consent and will 

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schedule an orientation session that describes the study goals and provides an 
opportunity to go over the informed consent.  
In order to decrease burden of the potential recruitment pool of participants, cognitive, 
motor, and physical function measurements will be shared between this study Effects of 
Acute Exercise on Functional Magnetic Resonance Spectroscopy Measures of GABA in 
Aging and Chronic Stoke (IRB00001334) and Graded Intensity Aerobic Exercise to 
Improve Cerebrovascular Function and Performance in Aged Veterans (IRB00106626) 
as all studies administer the same assessments.  
 
Healthy subjects will also be recruited via the Emory University Alzheimer Disease 
Research Center (ADRC) Registry.  Written permission from all patients is recorded on 
a signed informed consent form before inclusion in the ADRC Registry. This consent 
requires that the patients be willing to complete detailed histories, undergo 
comprehensive neurological and neuropsychological evaluations on an annual basis; 
submit blood for ascertainment of genetic information and establishment of 
lymphoblastoid cell lines; and agree to be contacted regarding participation in research 
projects of Emory investigators.   
CDW/VINCI data will be used to identify potential research participants. Veterans who 
are age 65 or older and who live within 20 miles of the Atlanta VA Health Care System 
will be identified and contacted via mail and then subsequently by phone. Addresses 
and phone numbers will be used for recruitment only and the information will be verified 
as current and accurate in CPRS prior to use.  
Additionally, participants may be recruited from word of mouth, newspaper 
advertisement, and study flyer distribution within the Atlanta VA Health Care System 
and surrounding community.  
Individuals will be provided a copy of the informed consent and will be scheduled for an 
orientation session that describes the study goals and provides an opportunity to go 
over the informed consent. The PI/Co-Investigator or their trained and qualified 
colleagues will go over and describe the consent in a private office of the 
PI/Coinvestigator.  
7.  Statistical Analysis: 
Statistical Analysis for Specific Aim 1 
Specific Aim 1 is to determine whether there will be a statistically significant difference in 
the cerebral perfusion data between the two groups (Spin and Control) following the 
intervention. We will assess the perfusion values jointly using a linear mixed-effects 
model to determine whether the mean change in perfusion between the groups is 
significantly different. For the model the fixed effect will be group (Spin vs Control) and 
the random effect will be time (Pre vs Post). We expect that modeling the outcomes 
jointly will increase the statistical power. This model will enable us to estimate the 

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overall effects of time and the interventions, and most importantly, how the effects of the 
interventions differ with time. Additional analyses will use multiple regressions to 
describe the effect of participant demographics such as gender, race, age, hypertensive 
status as well as MoCA score. A false discovery rate (FDR) of q = 0.05 will be 
calculated and used to correct for multiple tests and effect sizes will be computed. 
Statistical Analysis for Specific Aim 2 
Specific Aim 2 is to determine the impact of an aerobic intervention on CVR. Similar to 
Aim 1, we will test each BOLD change value jointly using a linear mixed-effects model to 
determine whether the mean change of the groups is significantly different across the 
time points (Pre and Post). Fixed effect will be group (Spin vs Control) and the random 
effect will be time (Pre vs Post). Additional analyses will use multiple regressions to 
describe the effect by participant demographics (gender, race, age, and hypertensive 
status) or by MoCA score. An FDR of q = 0.05 will be calculated and used to correct for 
multiple test and effect sizes will be computed. 
Statistical Analysis for Specific Aim 3 
The task fMRI BOLD images will be processed for slice-timing correction, and each 
image volume will be corrected for rigid-body head motion. The volume registered 
images will be inspected for artifacts induced by motion, cardiac pulsation and 
respiratory cycles and removed spatio-temporally using Independent Component 
Analysis (ICA). These artifact-free images will then be spatially transformed to MNI 
space using linear and non-linear co-registration algorithms. Following this spatial 
transformation, the images will be smoothed within the brain to increase the signal-
tonoise ratio. Then the images will be scaled to accurately determine the relative 
percent signal change in BOLD induced by the task. Finally, task-induced BOLD 
changes (ΔBOLD) from pre- to post-aerobic intervention and corresponding 
hemodynamic response functions are quantified using deconvolution technique.  
Since the goal of this aim is to quantify the impact of baseline physiologic measures (ie, 
resting blood flow and CVR) on task-induced BOLD changes, we plan to accomplish 
this task by modeling the contributions of perfusion and CVR to ΔBOLD responses. The 
equations below describe our simple modeling approach using linear regression: 
Δ𝐵𝑂𝐿𝐷𝑖,𝑅𝑂𝐼=𝐴+𝐵·𝐶𝐵𝐹𝑖,𝑅𝑂𝐼 +𝐶·𝐶𝑉𝑅𝑖,𝑅𝑂𝐼+𝐷·(𝐶𝐵𝐹𝑖,𝑅𝑂𝐼 × 𝐶𝑉𝑅𝑖,𝑅𝑂𝐼) 
Where subscript i=pre or post session, ROI refers to the regions of interest, and 
coefficients A is the modeled intercept, B and C are modeled slopes for perfusion and 
CVR contributions, and D is modeled slope for the interaction between perfusion and 
CVR respectively. We will compare the slopes obtained for pre and post exercise to 
explore (a) how each of the baseline measures (ie, perfusion and CVR) change in 
response to exercise, and (b) within each condition (pre or post), disentangle perfusion 
and vascular influence on task-induced BOLD change. Also, modeling for the interaction 
will account for the coupling effect which by itself can provide insightful information in 
terms of exercise-induced perfusion-CVR coupled effects. We plan to carry out the 

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above processing and modeling at the ROI level as it renders more detection power and 
is computationally less intensive. From a statistical standpoint, we will compute the F 
score to test the significance of overall fitting of the model, and we will also obtain the t 
score for each predictor (perfusion and CVR) to test the significance of their association 
with change in measured variable (ΔBOLD). To evaluate responsiveness to training and 
its impact on the model, post hoc analysis will include stepwise multiple regression to 
evaluate delta VO2 on perfusion and CVR in a-priori ROIs as well as behavioral 
outcomes. 
Cardiovascular Fitness Assessment 
The YMCA test uses an “extrapolation” method in which heart rate workload values are 
obtained at two to four points and extrapolated to predict workload at estimated 
maximum heart rate (220 - age). VO2 max is then calculated from predicted maximum 
workload. For YMCA submax, R=0.86, SEE=10% of the predicted when compared to 
V02 max protocols.37 In addition to this calculation, inspired and expired gases will be 
sampled during the YMCA test by a COSMED metabolic CPET via a facemask. Oxygen 
and carbon dioxide excretion will be measured allowing for %VO2 throughout the test as 
well as a measurement anaerobic threshold.  
Behavioral and Self-Report Data  
The analysis plan for behavioral performance will include the following dependent 
variables: semantic fluency performance and the motor tests, MOCA, and V02 submax, 
and each self-report outcome. Paired t-tests will be performed to test for a pre- to post 
effect on fluency and motor skills. Similarly, subscale scores and total scores will be 
evaluated pre to post intervention for each self-report measure. Spearman’s correlations 
(rs) will be used to correlate behavioral performance to primary outcomes and a mixed 
regression will be used to assess the influence of session (pre and post) on outcomes. 
REDCap 
This study will utilize REDCap issued through the Atlanta Veterans Health Care System. 
Only deidentified data will be entered in REDCap by VA credentialed research 
personnel to run data analysis. 
Power Analysis and Sample Size 
For Aim 1, we used preliminary data comparing older active adults to older sedentary 
adults. Effect size for difference in inferior frontal perfusion for a small sample (n=10) 
was d=-2.740. If this effect size is taken as an estimate of the effect size for change in 
the Spin group with n=44 and α FDR-corrected to 0.0261, then power approaches 1.00. 
A more conservative estimated change in perfusion being half the effect, with the 
standard deviation remaining constant, would produce an effect size of 1.370. With the 
same n and α as above, the power still approaches 1.00. The required effect size to 
achieve a power of 0.80 would be d=0.5, which would seem quite achievable given our 
preliminary data. Hence, the power should be more than adequate and seems plausible 
based on what we know. Because we want to maintain sensitivity at this level, the study 
is powered mainly to this Aim, while power for Aims 2 and 3 is more than adequate. For 

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example, for Aim 3, with α < .05, minimum power of 0.80 and 88 subjects, we have the 
power to detect an increase in R2 as small as 0.111 in each ROI. We have detected 
significant correlations between BOLD response in M141 and IFG42 with smaller sample 
sizes (n=36 and n=41, respectively). Accounting for much less than 11% of the variance  
in criterion variables with the predictors would be too little variance to provide 
information useful for the design of future clinical trials. Hence, we should have the 
power to detect effects large enough to impact future clinical trials.  
For behavioral data, we estimate the effect size for semantic fluency from 2 sources of 
data using the same treatment we will use for this study. For our lab the effect size for 
change in the Spin group was d=1.804, and for the preliminary data from an ongoing 
study the effect size for change in semantic fluency was d=1.41013 Using the more 
conservative of the two estimates, n=44 and a FDR corrected α=0.0261, power 
approaches 1.00. Again, an effect size of d=0.5 would achieve a power of 0.80, which 
seems quite achievable given the large effect sizes in two independent samples. Use of 
the Control in this instance is problematic because of a large negative outlier, yielding a 
large negative mean (-2.000, indicating a loss of semantic fluency) and a large standard 
deviation. Even so, these data yield an effect size of d=0.886, but these data are not 
stable enough to yield a good estimate of between-group effect size. With n=44 per 
group and α=.05 (FDR corrected), an effect size of d=0.64 would yield a power of 0.80. 
Based on the strong effect size for Spin, we believe this is an achievable effect size for 
a between-group analysis based on what we know about the Spin intervention. 
8. Adverse event reporting: 
In the case of a reportable event, the Principal Investigator will follow the current Atlanta 
VA Research and Development operating procedure for reporting.  This includes 
notifying the Emory IRB within the appropriate time period of any adverse event 
occurring. 
All study staff will be trained on proper reporting procedures of adverse events (i.e.- 
contact emergency medical services for immediate medical emergency and later the 
Principal Investigator, if not present). The PI will notify the IRB and VA SIO of any 
reportable events.  
9. Data and safety monitoring plan (DSMP): 
This is a minimal risk protocol and therefore data will not be reviewed by a Data 
Safety Monitoring Board (DSMB) or Data Monitoring Committee (DMC).  
Protection Against Risk 
Several precautions will be made to reduce the risk of exercise-related injuries: 
• 
The exercises are carefully designed with warm-up, stretching and cooling down 
components to minimize injuries; 

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• 
Written instructions highlighting some fundamental guidelines all study 
participants should do to ensure that they are exercising safely will be provided to 
all study participants; 
• 
For those individuals who are extremely de-conditioned, frequent rest periods 
and exercise from a sitting position will be offered at the beginning of the training 
period; 
• 
Additionally, the pre/post testing carries minimal risks due to the sub-maximal 
nature of the fitness testing.  As per the YMCA protocol, “physician supervision is 
not necessary with sub-maximal testing in low to moderate risk adults.” (ACSM’s 
Health Related Physical Assessment Manual, 2007). 
• 
At each exercise session, participants will be questioned about the presence of 
musculoskeletal symptoms; 
• 
If a participant experiences a significant illness requiring mobility restriction, 
surgery or hospitalization, the project coordinator will contact the participant’s 
primary physician, physician assistant, or nurse practitioner for clearance to 
return to the intervention classes.  
• 
If adverse symptoms develop a 1-week hiatus from the exercise session will be 
enforced, and during this time the participant will perform static stretching 
exercises.  A slow reintroduction of the exercise program will follow all hiatuses; 
• 
The instructors/evaluators will be instructed to be alert for the emergence of 
symptoms of angina and shortness of breath. Participants will be instructed to 
discontinue exercise if there is significant pain, weakness, or joint swelling after 
exercise.  
• 
We will ensure that that the site has immediate access to a phone and that 
provision of interventions and evaluations are undertaken in the immediate 
vicinity of a phone. All trainers and evaluators will also be encouraged to carry 
cell phones; 
• 
All activities will occur inside an air-conditioned facility because environmental 
extremes are poorly tolerated; 
• 
Every precaution will be taken to provide fluids, rest and other measures to 
ensure each participant is comfortable, safe and secure in the testing 
environment. 
Confidentiality of data is maintained by using research identification numbers that 
uniquely identify each individual. Safeguards are established to ensure the security and 
privacy of participants’ study records. The information collected from participants in this 
study has a low potential for abuse, since the data do not address sensitive issues. 
Nevertheless, appropriate measures are taken to prevent unauthorized use of study 
information. A research ID number will be used. The research records will be kept in a 
locked cabinet in the locked office of the PI. The files matching participants' names and 
demographic information with research ID numbers are kept in a separate locked room 
and are stored in a locked file that uses a different key from that of all other files. Only 
study personnel have access to these files. Electronic data will be stored in a password 
protected file on a secure network. Identifiers might be removed from the identifiable 

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private information that are collected. After that removal, the information could be used 
for future research studies. After the study is completed, procedures for long-term 
storage of VA data will be followed. 
FMRI data will be stored in a secure electronic environment in a locked office (6205 
A&B) at the Woodruff Memorial Research Building, 1639 Pierce Dr. Atlanta, GA 30322, 
without identifiers. 
 

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