An interventional study of Text Messaging Intervention in Physical Inactivity, Aging and Cognitive Ability, sponsored by University of Michigan. Recruiting at 1 site in United States. Open to participants aged 40 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-07-31.
Sponsored by University of Michigan · Not applicable, Interventional, and Other
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:
Participants will:
1,273 studies on the registry are indexed under Sedentary Behavior; 300 are open to participants now.
This study's planned enrollment of 150 is above the median of 60 across 1,076 interventional studies indexed under Sedentary Behavior.
Browse Sedentary Behavior studies →University of Michigan is the lead sponsor of 1,506 studies on the registry; 192 are open to participants now.
Of its 169 completed or terminated interventional studies of FDA-regulated products, 133 (79%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Short tests of memory and thinking, each scored out of 30. Lower scores suggest more difficulty; criteria give a range, either to include people with memory problems or to leave them out.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
MMSE and MoCA
Short tests of memory and thinking, each scored out of 30. Lower scores suggest more difficulty; criteria give a range, either to include people with memory problems or to leave them out.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants in this arm will receive motivational text messages that have been written and used in previous studies.
Behavioral: Text Messaging Intervention
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: 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.
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.
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.
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).
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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).
Plan to share: Yes — 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.
Supporting information: Study protocol, Statistical analysis plan, Informed consent form
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.
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.
Data sharing details ↗ · www.osf.io
No publications or documents are linked to this record.
Started May 2026 (actual). Primary completion is estimated for May 2027, 11 months after the start.
Of 733 non-industry interventional studies with no phase under Sedentary Behavior, half reached primary completion within 14 months of starting (the median), counting those still running; a quarter within 6 and three quarters within 31. This study's planned 11 months is below that.
Counting every sponsor, half of 741 studies reached it within 14 months; a quarter within 6 and three quarters within 31.
How these figures are worked out, and which studies are left out of them.
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