The Sedentary to Active Rising to Thrive (START) Trial

The goal of this behavioral clinical trial is to compare two different ways of becoming less sedentary and more active in 60 older adults at elevated risk of becoming frail.

The main question this project aims to answer are whether participants in each intervention are able to gradually replace 30 minutes of sedentary (sitting-like) behavior with very light walking over 60 days.

There are other questions this project aims to answer that include:

1. whether it is easier to replace sedentary behavior with one 30-minute walking bout or three 10-minute walking bouts
2. whether becoming less sedentary and more active leads to feeling better, have less stress, pain, and fatigue and have more confidence in becoming more regularly active
3. whether becoming less sedentary and more active leads to better regulation of inflammation and metabolism

Participants will be randomized into one of two sedentary reduction behavior programs; one program that gradually replaces sedentary time with one 30-minute walking bout and the other program that gradually replaces sedentary time with three 10-minute walking bouts in the morning, afternoon, and evening. Researchers will compare both programs to see which one is easier to achieve and maintain over 60 days.

Initiating and maintaining habitual physical activity is difficult for sedentary older adults, particularly those encumbered by health challenges. The 2018 US Physical Activity Guidelines recommends that all adults perform ≥150 minutes/week of physical activity and reduce sedentary behaviors. Yet, traditional approaches to increase physical activity do little to address sedentary behavior reduction, especially for older adults. Lower sedentary behavior is associated with improved biological and psychosocial health-independent of meeting physical activity guidelines. Thus, there remains a critical need to implement and evaluate a structured way to reduce sedentary behavior as a potential pathway for habitual physical activity engagement.

This project aims to test two prescribe-able and feasible strategies to initiate and incorporate sedentary behavior reduction into daily lifestyle with remote monitoring. The interventions are an inexpensive and low burden approach to reduce sedentary behavior and promote habitual physical activity. Moreover, accelerometer-based outcomes of sedentary behavior are novel in intervention settings, particularly when measured in free-living, real-world settings. Lastly, this project directly addresses a gap of successful remotely deployable interventions geared to initiate and build activity into daily life by replacing sedentary time among older adults.

Aim 1. Explore the effectiveness of 2 interventions to reduce sedentary time in pre-frail older adults over 2 months

Hypothesis 1a. Each intervention will reduce objectively measured daily sedentary time from baseline levels over 2 months.

Hypothesis 1b. The continuous intervention will result in more reduction of objectively measured sedentary time than the bouts intervention.

Aim 2. Explore the dose-response relationship between sedentary time changes and patient-reported outcomes that include fatigue, fatigability, anxiety, general and exercise-based self-efficacy, stress, pain, and mood over 2 months

Hypothesis 2: Decreased daily sedentary time over 2 months is associated with decreased fatigue, fatigability, anxiety, stress, and pain, and increased general and exercise-based self-efficacy and mood over 2 months.

Aim 3. Explore the dose-response relationship between sedentary time changes and biomarkers of frailty-related inflammation, including serum interleukin (IL-6) (pg/mL) and tumor necrosis factor (TNF) -alpha receptor 1 (pg/mL) over 2 months

Hypothesis 3. Decreased daily sedentary time is associated with decreased serum (IL-6) and TNF-alpha receptor 1 over 2 months.

Aim 4. Explore the dose-response relationship between changes in sedentary time with biomarkers of glucose and lipid metabolism (glucose, insulin, total cholesterol (TC), low-density lipoprotein cholesterol (LDLC), triglycerides, high-density lipoprotein cholesterol (HDLC)), a cytokine marker related to frailty (Growth/Differentiation Factor-15; (GDF-15), hemoglobin A1C (hbA1c), non-esterified free fatty acid, and untargeted metabolomics-based markers of energy regulation.

Hypothesis 4. Decreased daily sedentary time is associated with decreased levels of blood glucose, insulin, TC, LDLC, triglycerides and increased HDLC, decreased GDF-15, decreased hbA1c, decreased non-esterified free fatty acid, and lower circulating metabolites necessary for energy regulation over 2 months.

Aim 5. Explore the dose-response and diurnal relationships between changes in sedentary time and interstitial glucose continuously monitored over 24 hours for 14 consecutive days using a Libre Pro sensor at baseline and 2 months later

Hypothesis 5. Decreased sedentary time is associated with decreased overall glucose and different time-of-day glucose levels, coefficient of variation, % of time in glucose at various ranges (e.g., ≥200, ≥180, ≥140, 70-180, 70-140, \<70, \<54 mg/dL), mean daily difference, and mean amplitude of glycemic excursion) over 2 months.

Eligibility Criteria:
Inclusion Criteria:

* Adults aged ≥65 years
* Pre-frail defined as having 1-2 of the following criteria:
* Self-reported unintentional weight loss
* Self-reported fatigue
* Self-reported low activity
* Slowness measured during a 4-m walking test
* Weakness measured with grip strength
* Self-reported regular physical activity \<20 minutes/day
* Self-reported willingness to work up to walking for 30 minutes/day
* Self-reported ability to find a place to walk for up to 30 minutes/day
* Agree to all study procedures and assessments
* Ability to provide informed consent

Exclusion Criteria:

* Self-reported diabetes
* Self-reported problems related to alcohol or drugs
* Self-reported inability to walk across a room
* Self-reported use of a walker
* Self-reported requirement of medical supervision when engaging in physical activity
* Fallen \>2 times in the past month
* Participation in another clinical trial
* Plan to move out of the area within 6 months
* Inability to provide self-transportation to study assessment visits
* Inability to complete a usual-paced 400m walking test within 15 minutes without sitting or the help of another
* Uncontrolled resting hypertension (\>160/90 mmHg)
* Cognitive impairment determined using the Montreal Cognitive Assessment Test