Feasibility and Acceptability of Implementing a Clinic-based Physical Activity Coaching Intervention in People With Premanifest and Early Stage HD

The investigators have previously developed and evaluated a physical activity behavioral
change intervention in people with early-mid stage HD (Engage-HD). In a study conducted in
the United Kingdom, self-reported physical activity, self-efficacy for exercise, and
cognition were increased for those in the coaching intervention group compared to a social
contact control group. This intervention has not yet been applied to individuals with
pre-manifest (prior to onset of clinical symptoms) and early stage HD, where it may be most
critical to engage in exercise. To date, no study has prospectively evaluated a physical
activity intervention to facilitate exercise uptake in these earliest stages. This study will
explore the feasibility and acceptability of the Engage-HD intervention in 14 individuals
with pre-manifest and early stage HD. The intervention will entail one face-to-face coaching
session (approximately 1 hour), and three remote video sessions (via secure Webex connection
via computer or smart phone, or phone call if internet/smart phone is not available to
participant) lasting approximately 20 minutes. Participants will also be given FitBit
wearable activity monitors to allow for self- monitoring of physical activity for use during
the 4-month intervention. Participants will be evaluated at baseline and again 4 months later
on a range of exploratory outcomes including physical activity, self efficacy,
disease-specific motor and cognitive function, walking endurance and strength. Results from
this study will be used to make relevant adaptations to prepare for a multi-site randomized
controlled trial.

Inclusion Criteria:

- For premanifest - Confirmatory genetic testing for Huntington disease (HD) and
diagnostic confidence score of 0-3 on Unified Huntington Disease Rating Scale,
indicating pre-manifest disease state. For manifest HD - Confirmatory genetic testing
for HD or confirmed clinical diagnosis of HD by neurologist

- Successful completion of Physical Activity Readiness Questionnaire (PAR-Q), or medical
clearance from General Practioner

- For potential participants over age 60, a minimum score of 24 on the Mini-Mental State
Examination (MMSE) (completed within 3 months) will be required for capacity to
consent.

- For potential participants age 60-65, successful pass of electrocardiogram screen will
be required.

Exclusion Criteria:

- Musculoskeletal injury that would interfere with participation in an exercise program

- Currently participating in a structured exercise program 3 times per week or more

- Uncontrolled psychiatric or behavioral problems that would interfere with
participation in an exercise program