Effects of Exercise Intervention on Aging-related Motor Decline (EIAMD)

Effects of Exercise Intervention on Aging-related Motor Decline (AGING)

The purpose of this research study is to test whether differing levels of physical fitness affects patterns of motor dexterity and brain activity that have been shown to differ due to aging. Testing will take place at the Atlanta VA Medical Center and at Emory University.

Participants will be healthy adults within the target age range of 60-85 for the study. The study will require multiple visits over 15 months. There will be about 64 people volunteering for this study.

Study Overview

• Status: Completed
• Conditions: Exercise; Aging
• Intervention / Treatment: Behavioral: Stretching Exercise Intervention; Behavioral: Aerobic Exercise Intervention; Behavioral: Self Monitoring

Detailed Description

The U.S. Census reports over 14 million U.S. Veterans (>63%) are beyond mid-life (>55 years). Declines in upper extremity motor performance respective of strength and dexterity are well documented within this age cohort). Recent cross-sectional research has discovered that aging related motor deficits may be influenced by a loss of interhemispheric inhibition (IHI) between primary motor cortices. However, this loss may not be an inevitable consequence of aging. Work from previous VA OAA Predoctoral and CDA-1 awards have shown that aerobic fitness may serve to mitigate losses in interhemispheric inhibition assessed by both functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS). That is, individuals who are aerobically fit show higher levels of IHI and improved dexterity and reaction times.

In light of new evidence from the investigators' lab's recent cross-sectional studies, physical activity over the long term (at least 2-5 years) may serve to alter levels of IHI and improve motor performance in the upper extremity. Aerobic exercise may provide a mechanism (reduced loss of interhemispheric inhibition) that could serve to improve motor function, but the neural mechanism responsible for such effects remains unclear. Previous investigations of interhemispheric communication and exercise have been limited by nature of inquiry, as cross-sectional research cannot measure changes over time in participants. As such, it is currently unknown how exercise may directly affect levels of interhemispheric communication and motor performance.

Behavioral interventions (motor strength and coordination) have been shown to be effective in improving upper extremity motor performance in older adults, however the duration of these gains appear to be short-lived. After as little as a few weeks of detraining, motor strength and coordination in the upper extremity rapidly begins to return to pre-intervention levels. Evidence from exercise interventions assessing gait and locomotion have shown that exercise programs over a longer term (>6 months) are associated with improved proprioception, fewer falls and better balance. However, the comparison of outcomes of upper extremity function in elderly adults respective of exercise duration remains largely unexplored. In addition to comparing the effects of short-term exercise (3 months) versus behavioral training (3 months) on upper extremity function, the current proposal will evaluate if a longer-term (6 months) exercise program can maintain or enhance upper extremity function and associated levels of interhemispheric inhibition.

The current study proposes the next logical step in my line of research and directly investigates the effects of exercise in an intervention with sedentary older Veterans (50-80 years), a group most likely to exhibit aging-related motor deficits. The investigators propose to enroll 40 Veterans into an upper extremity dexterity improvement program involving behavioral and exercise components. The behavioral intervention is a muscle coordination training previously shown to improve unimanual motor performance in older adults. The exercise intervention is a supervised group cycling regimen. The figure below shows the study design. Interhemispheric communication will be assessed with fMRI, and TMS.

• Study Type: Interventional
• Enrollment (Actual): 33
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Georgia
    • Decatur, Georgia, United States, 30033
      • Atlanta VA Medical and Rehab Center, Decatur, GA

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 60 years to 85 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Living persons between 60 and 85 years of age

Exclusion Criteria:

• unmanaged diabetes
• participants completing vigorous exercise per week
• participants whose profession requires vigorous physical labor
• contraindication to magnetic resonance imaging

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Stretching Exercise Intervention; A. Light stretching and balance exercises under supervised trainer. 3 times per week for 20-45 minutes. HR will be targeted to be under 50% of age-related maximum.	Behavioral: Stretching Exercise Intervention; A. Light stretching and balance exercises under supervised trainer. 3 times per week for 20-45 minutes. HR will be targeted to be under 50% of age-related maximum.
Experimental: Aerobic Exercise Intervention; B. Interval aerobic cycling under supervised trainer. 3 times per week for 20-45 minutes. HR will be targeted between 50-85% of age-related maximum.	Behavioral: Aerobic Exercise Intervention; Supervised weekly exercise. 3 bouts of 45 minutes weekly on a cycle ergometer. HR will be kept at 75% of age-related maximum.
Experimental: Self Monitoring Intervention; C. 6 month self-monitored training phase during which time participants will exercise using a take home bike ergometer.	Behavioral: Self Monitoring; 6 month self-monitored training phase during which time participants will exercise according to prescribed regimen (cycling)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Estimate Cardiovascular Efficiency After Aerobic Exercise	Estimate of Volume of oxygen consumption (VO2peak) using YMCA protocol for cardiovascular assessment.	Baseline, 12 weeks, 24 weeks
Estimate of Cardiovascular Efficiency After Balance Training	Estimated VO2peak using YMCA cycle test completed over nine to twelve minutes.	Baseline, 12 weeks, 24 weeks
Silent Period Duration After Exercise Cycling Program	Duration of ipsilateral silent period from Transcranial magnetic stimulation measured in milliseconds	Baseline, 12 weeks, 24 weeks
Silent Period Duration for Balance Group	Ipsilateral silent period duration as assessed by TMS	Baseline, 12 weeks, 24 weeks
fMRI Interhemispheric Inhibition Improvement After Aerobic Exercise	Participants who exercise will evidence larger increases in interhemispheric inhibition as assessed by functional magnetic resonance measured by a z-normalized area under curve of right primary motor cortex. The area under the curve is an estimate of the fMRI hemodynamic response impulse response function. A higher number of AUC indicates less interhemispheric inhibition. In contrast, a lower number in this analysis indicates higher interhemispheric inhibition.	Baseline to 24 Weeks with cross-over
fMRI Interhemispheric Inhibition Improvement After Balance Training	Area under the curve of fMRI measures of right motor cortex BOLD profile will remain similar to pre measurements. The BOLD profile is the z-normalized area under the curve value of the fMRI impulse response function. A higher number indicates less interhemispheric inhibition.	Baseline, 12 weeks, 24 weeks
Comparison of Cardiovascular Efficiency for Aerobic Exercise First Group After Home-based Intervention	Comparison of home based aerobic exercise intervention to assessments made after completion of crossover intervention in Participants receiving aerobic condition first. VO2peak estimation completed using the YMCA protocol investigating overall volume of oxygen consumption as a function of heart rate during work loads. Estimated VO2 peak values are in ml/kg(min).	24 and 48 weeks
Comparison of Cardiovascular Efficiency for Balance Exercise First Group After Home-based Intervention	VO2peak estimation completed using the YMCA protocol investigating overall volume of oxygen consumption as a function of heart rate during work loads.	24 and 48 weeks
Comparison of Silent Period Duration After Aerobic Exercise	Comparison of silent period duration at 24 weeks compared to baseline	Baseline, 12 weeks, 24 weeks
Comparison of Silent Period Duration After Balance Exercise	Comparison of Home based training effects on TMS measures of silent period duration as compared to facility based exercise programs.	24 and 48 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Target Heart Rate Zone for Balance First Participants	Heart rate in aerobic target zone is measured in percentage of time in at least 50% of participants heart rate reserve.	24 and 48 weeks
Target Heart Rate Zone After Aerobic Exercise First	Targeted Heart Rate Zone among participants compared among short term exercise groups	24 and 48 weeks
Heart Rate Workload After Home Based Intervention	Measured heart rate after home based intervention Technical implementation at the facility level prevented acquisition of these metrics until late in the project.	24 and 48 weeks

Collaborators and Investigators

• Sponsor: VA Office of Research and Development
• Investigators: Principal Investigator: Keith M. McGregor, PhD MS BA, Atlanta VA Medical and Rehab Center, Decatur, GA

Publications and helpful links

General Publications

• McGregor KM, Crosson B, Mammino K, Omar J, Garcia PS, Nocera JR. Influences of 12-Week Physical Activity Interventions on TMS Measures of Cortical Network Inhibition and Upper Extremity Motor Performance in Older Adults-A Feasibility Study. Front Aging Neurosci. 2018 Jan 4;9:422. doi: 10.3389/fnagi.2017.00422. eCollection 2017.
• Nocera J, Crosson B, Mammino K, McGregor KM. Changes in Cortical Activation Patterns in Language Areas following an Aerobic Exercise Intervention in Older Adults. Neural Plast. 2017;2017:6340302. doi: 10.1155/2017/6340302. Epub 2017 Mar 6.
• McGregor KM, Crosson B, Krishnamurthy LC, Krishnamurthy V, Hortman K, Gopinath K, Mammino KM, Omar J, Nocera JR. Effects of a 12-Week Aerobic Spin Intervention on Resting State Networks in Previously Sedentary Older Adults. Front Psychol. 2018 Nov 27;9:2376. doi: 10.3389/fpsyg.2018.02376. eCollection 2018.

Study record dates

Study Major Dates

• Study Start (Actual): January 14, 2013
• Primary Completion (Actual): July 7, 2018
• Study Completion (Actual): August 1, 2019

Study Registration Dates

• First Submitted: February 5, 2013
• First Submitted That Met QC Criteria: February 5, 2013
• First Posted (Estimate): February 8, 2013

Study Record Updates

• Last Update Posted (Actual): February 20, 2020
• Last Update Submitted That Met QC Criteria: February 5, 2020
• Last Verified: February 1, 2020

More Information

Terms related to this study

• Keywords: Exercise; Magnetic Resonance Imaging; Aging; Transcranial Magnetic Stimulation
• Other Study ID Numbers: E0956-W; 2012-060697 (Other Grant/Funding Number: Veterans Affairs)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No