The Promotion of Physical Activity for the Prevention of Alzheimer's Disease in Adults With Down Syndrome

MVPA was assessed using an ActiGraph tri-axial accelerometer.

Working memory, processing speed, multitasking, and episodic memory will be assessed at baseline, 6 and, and 12 months, using tests selected from the widely used Cambridge Neuropsychological Test Automated Battery (CANTAB, Cambridge Cognition, LTD, Cambridge, UK) for Down syndrome. The CANTAB for Down syndrome uses a battery of tests including multitasking, episodic memory, executive function and processing speed.

Maximal treadmill tests (modified Balke protocol) will be completed at baseline, 6, and 12 months

Quality of life will be assessed at baseline, 6, and 12 months with the Personal Well-Being Index Intellectual Disability, which contains 7 items, each corresponding to a quality of life domain: standard of living, health, life achievement, personal relationships, personal safety, community connectedness, and future security. Participants answer questions on a 0-4 scale, with 0 being least happy and 4 being most happy.

Brain volume will be measured using structural MRI at baseline, 6, and 12 months

Functional connectivity will be measured using resting state MRI (rsMRI) at baseline, 6, and 12 months.

Functional connectivity will be measured using arterial spin labeling at baseline, 6, and 12 months

Retention will be measured by the percentage of participants who complete the 12 month intervention, defined as completing the 12 month outcome assessments.

Session attendance for both group MVPA and education/support sessions from baseline to 12 months will be obtained from records maintained by the health educator, and expressed as the percent of possible sessions. Attendance at group MVPA sessions will be defined as being logged in to the video conference and remaining on the screen for the entire 30-min session. Attendance at individual support/education sessions, for the both exercise and UC conditions, will be defined as answering the FaceTime call, and being present on screen for the entire session.

Use of recorded exercise sessions will be tracked using Dropbox which provides information on how many times each user watched a video.

Safety will be measured by number of participants reporting a serious adverse event, i.e., any untoward medical occurrence that results in death, is life-threatening, requires inpatient hospitalization or results in persistent or significant disability/incapacity.

Weight will be measured in light clothing on a calibrated scale (Model #PS6600, Belfour, Saukville, WI) to the nearest 0.1 kg.

Standing height will be measured with a portable stadiometer (Model #IP0955, Invicta Plastics Limited, Leicester, UK).

Waist circumference will be assessed using a waist tape measure.

The energy expenditure of sessions will be collected by a portable metabolic system at random timepoints across the 12 month study.

Functional lower extremity strength will be assessed using the Five Times Sit to Stand

Functional mobility will be assessed using the Timed Up and Go.

Upper body strength will be assessed using hand grip dynamometer

Activities of daily living will be assessed using the Waisman Activities of Daily Living scale. This scale contains 17 questions, each item is rated as 0="does not do", 1="does with help", or 2="does independently / on own. A higher score indicates greater independence.

Caregiver burden will be assess using The Modified Caregiver Strain Index. The tool has 13 questions that measure strain related to care provision. Scoring is 2 points for each 'yes', 1 point for each 'sometimes', and 0 for each 'no' response. Scoring ranges from 26 to 0; a higher score indicates a higher level of caregiver strain.

Caregiver stress will be assessed by the Caregiver Self-Assessment Questionnaire. This questionnaire is 18 questions, 16 with yes or no responses, and 2 ranking questions. Typically a higher score indicates a higher level of caregiver stress.

Caregiver quality of life will be assessed by the Adult Carer Quality of Life Questionnaire. The Adult Carer Quality of Life Questionnaire is a 40-item instrument that measures the overall quality of life for adult carers. Scores on the have a possible range of 0 to 120 with higher scores indicating greater quality of life.