Motivating Activity Through Text Communications - Helping Adults Increase Movement (MATCH AIM)

Motivating Activity Through Text - Comparing Human and AI Messages (MATCH AIM) Trial

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

Study Overview

• Status: Not yet recruiting
• Conditions: Aging; Physical Inactivity; Behavior Change; Cognitive Ability
• Intervention / Treatment: Behavioral: Text Messaging Intervention

• Study Type: Interventional
• Enrollment (Estimated): 150
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Ann M Mehringer; Phone Number: 734-647-6050; Email: amehring@umich.edu

Study Locations

• United States
  • Michigan
    • Ann Arbor, Michigan, United States, 48109
      • University of Michigan
      • Principal Investigator: David E Conroy, PhD
      • Contact: David E Conroy, PhD; Phone Number: 734-647-8404; Email: deconroy@umich.edu
      • Contact: Ann M Mehringer; Phone Number: 734-647-6050; Email: amehring@umich.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

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 Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
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.	Behavioral: 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: Random AIM (month 1): Messages are sent at random times within the participant's window to collect baseline data on their behavioral responses.; 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.
Experimental: Newly created text messages; Participants in this arm will receive motivational text messages that have not been used in previous studies.	Behavioral: 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: Random AIM (month 1): Messages are sent at random times within the participant's window to collect baseline data on their behavioral responses.; 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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Daily Step Count	The primary outcome measure is the average daily step count, which is assessed using a blinded, research-grade activPAL activity monitor, worn on the thigh for a 7-day assessment period.	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.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mechanisms of Behavior Change for Adherence: Habit Strength	Habit Strength will be assessed using the Behavioral Automaticity Index from the Self-Report Habit Index to measure how automatic the exercise behavior has become. Scores are calculated as the average item responses and range from 1 to 7 with higher scores reflecting greater experienced automaticity (i.e., stronger habits).	These secondary outcomes are collected at the same major time points as the primary outcome: baseline (month 0), post-intervention (month 3), and follow-up (month 6).
Mechanisms of Behavior Change for Adherence: Exercise Identity (Reflective)	Exercise Identity will be assessed using the Exercise Identity Scale to see how much participants view themselves as "exercisers". Scores are based on the average item response and range from 1 to 7 with higher scores representing a stronger exercise identity.	These secondary outcomes are collected at the same major time points as the primary outcome: baseline (month 0), post-intervention (month 3), and follow-up (month 6).
Mechanisms of Behavior Change for Adherence: Automatic Affective Evaluations	Automatic Affective Evaluations will be assessed using a Single-Category Implicit Association Test (SCIAT) to assess non-conscious attitudes toward physical activity. Scores are standardized mean differences of response times between blocks of trials where physical activity is paired with unpleasant attributes and blocks of trials where physical activity is paired with pleasant attributes. Higher scores indicate more favorable automatic affective evaluations of physical activity.	These secondary outcomes are collected at the same major time points as the primary outcome: baseline (month 0), post-intervention (month 3), and follow-up (month 6).
Ambulatory Cognitive Function: Processing Speed	Processing Speed will be assessed with the Mobile Monitoring of Cognitive Change (M2C2) Symbol Search Task. Scores are based on response times for accurate trials so there is no fixed range for scores. Shorter response times indicate faster (better) processing speed; longer response times indicate slower (worse) processing speed.	These secondary outcomes are collected at the same major time points as the primary outcome: Baseline (month 0), post-intervention (month 3), and follow-up (6 month).
Ambulatory Cognitive Function: Working Memory Capacity	Working Memory Capacity will be measured using the M2C2 Grid Memory Task. Scores are based on response accuracy measured as a Euclidean distance score. Shorter distance scores indicate more working memory capacity; longer distance scores indicate less working memory capacity.	These secondary outcomes are collected at the same major time points as the primary outcome: Baseline (month 0), post-intervention (month 3), and follow-up (6 month).

Collaborators and Investigators

• Sponsor: University of Michigan
• Collaborators: National Institute on Aging (NIA)
• Investigators: Principal Investigator: David E Conroy, PhD, University of Michigan

Study record dates

Study Major Dates

• Study Start (Estimated): June 1, 2026
• Primary Completion (Estimated): May 3, 2027
• Study Completion (Estimated): August 2, 2027

Study Registration Dates

• First Submitted: May 4, 2026
• First Submitted That Met QC Criteria: May 11, 2026
• First Posted (Actual): May 18, 2026

Study Record Updates

• Last Update Posted (Actual): May 22, 2026
• Last Update Submitted That Met QC Criteria: May 21, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: physical activity; older adults; cognitive function; aging; motivation; text messaging; behavioral adherence
• Additional Relevant MeSH Terms: Behavior; Motor Activity; Sedentary Behavior
• Other Study ID Numbers: HUM00262651; P30AG086637 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: De-identified individual participant data (IPD) underlying the results reported in primary and secondary publications will be shared. This includes baseline behavioral metrics, coarsened demographics, post-intervention outcomes, and follow-up data. To protect participant privacy, all data will be stripped of direct identifiers, ages will be binned into 5-to-10-year bands, geographic markers restricted to broad regions, and timeline dates converted to "days since randomization." Raw, free-text qualitative journal entries will be suppressed entirely due to re-identification risks.
• IPD Sharing Time Frame: Data and supporting documentation will be made available concurrently with the primary peer-reviewed publication of the trial results and will remain accessible for 5 years post-publication. This immediate availability complies with the NIH Data Management and Sharing Policy.
• IPD Sharing Access Criteria: Access is restricted to qualified external researchers affiliated with an accredited academic or non-profit research institution. Applicants must submit a formal, written research proposal detailing a sound scientific hypothesis and an analytical plan, alongside documentation of local IRB approval/waiver. Approved requestors and their sponsoring institutions must sign a legally binding Data Use Agreement (DUA) that strictly prohibits any re-identification or external data-linking attempts.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No