This pilot study aims to test whether remote delivery of the exercise intervention provides a sufficient training stimulus. This pilot study will be remote and online-only, and will have no in-person interaction, data collection or intervention. 20 Participants will participate in a 12-wk, 3hrs/wk remote exercise intervention and in a pre- and a posttest remote testing session. We will use Zoom for all testing and exercise sessions.

Design: Repeated measures design: 20 participants will participate in the remote exercise intervention study with a pre-test and a post-test to investigate training effects on aerobic endurance, strength, balance and gait.

Intervention: The program we will be using is specifically developed for individuals with Down syndrome based on the Mann Method PT Principles. The MMPT Principles TM focus on a progressive program of therapeutic activity (cardiovascular activity), therapeutic exercise (foundational strengthening and hip strengthening activities), and neuromuscular rehabilitation (visual/vestibular and balance activities) to address the unique needs of individuals with Down syndrome. This program has been developed and successfully implemented in Down syndrome activity centers across the country. This program will be offered through Zoom. Intensity will be submaximal for both data collection and during the exercise sessions, and recorded with Polar heart rate monitors.

Measurements: We will use only field tests instead of the original lab-based testing for aerobic endurance, strength, balance and gait, and all tests will be conducted remotely.

Baseline measurements: height, weight, circumferences Aerobic endurance: 2 Minute Step Test: participant marches in place as fast as possible with a set height for how high to lift the knees, for two minutes. Outcome is heart rate and number of steps in two minutes.

Strength: 30 Second Chair Stand and 5 Times Chair Stand: participants starts seated, then stands up and sits down as fast as possible, first counting the number of times within 30 seconds, then timing the number of seconds for 5 times.

Balance: Timed Up and Go: This is a timed test where the participant stands up from a chair, walk 10ft, turn around, walk back and sit down again, as fast as possible. Modified CTSIB (Clinical Test on Sensory Information on Balance) and FICSIT-4 (Frailty and Injuries: Cooperative Studies of Intervention Techniques): Standing balance in different conditions and positions. Functional Reach Test: Reaching from a standing position as far as possible.

Gait: Comfortable and Fast Walking Speed, Observational Gait Analysis based on anterior, posterior and lateral video recordings of the participant's walking.

Additionally, participants (and/or parents/caregivers for the group with Down syndrome) will complete a health history questionnaire and physical activity questionnaire, a questionnaire about risk of falling (Short Falls Efficacy Scale-1) and about attitudes towards exercise (Health Matters Evaluation Toolkit).

Inclusion Criteria:

• Between 18 and 35 years old

• generally healthy

• sedentary (defined as being involved in less than 30 minutes of moderately-intense physical activity per day)

• additionally for the participants with Down syndrome:

  • diagnosis of Down syndrome trisomy 21 and
  • normal thyroid function or stable thyroid function (and medications) for at least 6 mo.

Exclusion Criteria:

• congenital heart disease;
• atherosclerotic or other vascular disease;
• asthma or other pulmonary disease;
• hypertension (defined BP >140/90 mmHg);
• blood pressure below 90/60 mmHg;
• history of pre-syncope or syncope;
• diabetes (defined as Hba1c of >7.5% or use of glucose lowering medication);
• severe obesity (defined as BMI >40);
• medications affecting heart rate, blood pressure or arterial function;
• anti-inflammatory medication including NSAIDS;
• current smoking and
• pregnancy.

De-identified individual patient data will be made available to other researchers upon request.