Recruiting

Text Messaging

Sponsor:

University of Michigan

Code:

NCT07593677

Conditions

Physical Inactivity

Aging

Cognitive Ability

Behavior Change

Eligibility Criteria

Sex: All

Age: 40+

Healthy Volunteers: Accepted

Interventions

Text Messaging Intervention

Study Details

Brief summary:

The goal of this clinical trial is to compare the effect of different types of text messages on physical activity levels of middle-aged and older adults and to determine whether these messages are effective in adults age 40 and older who are engaging in less than 90 minutes per week of moderate or higher intensity physical activity. The main questions it aims to answer are:

  • Which types of motivational messages show the greatest effects on changes in daily step counts in a 3-month precision text messaging intervention?
  • What are the effects of personalized text messages on automatic affective evaluations, habit strength (experienced automaticity), exercise identity, working memory capacity, and processing speed?

Participants will:

  • Wear a Fitbit activity tracker continuously for 3 months and are encouraged to continue wearing it through 6 months.
  • Wear an activPAL activity monitor on their thigh for 7-day assessment periods at the beginning of the study, at 3 months, and at 6 months.
  • Complete 3 cognitive assessments ("brain games") per day on their smartphone during the 7-day assessment periods at baseline, 3 months, and 6 months.
  • Be asked to set goals to increase their daily steps over the first 3 months of the study.
  • Receive up to 4 motivational text messages per day for 3 months to encourage physical activity.
  • Keep study-related apps (Fitbit app, AIM app, MetricWire app) open in the background on their smartphone.
  • Complete questionnaires at the beginning of the study, at 3 months, and at 6 months

Conditions

Physical Inactivity

Aging

Cognitive Ability

Behavior Change

Study ID

NCT07593677

Start date

May 11, 2026

Status verified date

Jul, 2026

Completion date

Aug 2, 2027

Anticipated

Primary completion date

May 3, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 40+

Healthy Volunteers: Accepted

Inclusion Criteria:

  • Be 40 years of age or older
  • Own a smartphone running an Android or iOS operating system
  • Have proficiency with the English language
  • Be capable of providing informed consent
  • Be able to perform moderate physical activity without restrictions
  • Be willing to complete the entire 6-month protocol
  • Be willing to establish a 12-hour window - beginning no later than 9:45 am and ending no later than 9:45 pm - for receiving text messages.

Exclusion Criteria:

  • Residing outside of the continental United States
  • Self-reporting 90 minutes or more of moderate-to-vigorous intensity physical activity per week
  • contraindications to normal physical activity as identified on the Physical Activity Readiness Questionnaire (PAR-Q)
  • Mobility restrictions that interfere with unassisted physical activity
  • Being pregnant or planning to become pregnant during the study
  • Planning to undergo surgery during the course of the study protocol
  • Having a prior diagnosis of Alzheimer's disease or a related dementia
  • Evidence of mild cognitive impairment as indicated by a mini-Montreal Cognitive Assessment (MoCA) test score of 12 or higher
  • Concurrent participation in another study involving weight loss or physical activity
  • Failure to respond to at least 85% of Ecological Momentary Assessment (EMA) prompts during the 7-day qualification phase.

Study Design

Enrollment

150 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Other

Interventions and Outcome Measures

Arms

active comparator: Validated library of text messages

Participants in this arm will receive motivational text messages that have been written and used in previous studies.

experimental: Newly created text messages

Participants in this arm will receive motivational text messages that have not been used in previous studies.

Interventions

Text Messaging Intervention

Participants will receive up to 4 motivational text messages per day during a self-selected 12-hour window. These messages focus on two content areas: 1) Move more, and 2) sit less. Delivery of these messages occurs in two phases:

1. Random AIM (month 1): Messages are sent at random times within the participant's window to collect baseline data on their behavioral responses.
2. Precision AIM (months 2 and 3): Messages are sent at optimized times based on person-specific models that are created from the individual's previous responses to text messages from month 1.

Primary outcome measure

  • Daily Step Count [ Time Frame: The activPAL is worn on the thigh for a 7-day assessment period before the intervention begins (baseline), after 3 months of intervention, and then again 3 months after the intervention is complete. The total time frame is 6 months. ]

Central Contacts and Locations

Central contacts

Ann M Mehringer

734-647-6050amehring@umich.edu

Locations

University of Michigan

Recruiting

Ann Arbor, Michigan, United States, 48109

Contacts

David E Conroy, PhD

734-647-8404deconroy@umich.edu

Ann M Mehringer

734-647-6050amehring@umich.edu

Principal Investigator:

David E Conroy, PhD

More Information

Sponsor

University of Michigan

Last update posted

Jul 31, 2026

Last verified

Jul, 2026

Keywords

  • physical activity
  • behavioral adherence
  • motivation
  • cognitive function
  • aging
  • older adults
  • text messaging

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-09. This information was provided to ClinicalTrials.gov by University of Michigan on 2026-07-31.