An interventional study of Sit Less, Move More (SLMM) for pregnant women in Pregnancy, Sedentary Behavior and Insufficient Physical Activity, sponsored by University of Central Florida. Recruiting at 1 site in United States. Open to female participants aged 18 Years to 45 Years. Per ClinicalTrials.gov, last updated 2026-08-25.
Sponsored by University of Central Florida · Not applicable, Interventional, and Prevention
Pregnant women are more sedentary (sit, recline, lie down more) on average than non-pregnant women (more than 12 versus less than 8 waking sedentary hours/day). Sedentary behavior has been related to psychological distress, pregnancy weight gain, impaired sleep and very large size infants, while adequate physical activity has been found to improve mental health, decrease risk of high blood pressure in pregnancy and lower risk of preterm birth infants (less than 37 weeks gestation). Decreased sedentary behavior and increased physical activity may be crucial and neglected lifestyle behavior changes that can be promoted to reduce these and other maternal health and birth outcome problems among pregnant women.
Interventions that decrease sedentary behavior (SB) and improve physical activity (PA) provide a path to improve maternal health and infant outcomes. Sedentary behavior (sitting, reclining, or lying while awake; activity energy expenditure of 1.5 metabolic equivalent of task [MET]) during pregnancy is a modifiable factor associated with adverse maternal health (e.g., psychological distress, gestational weight gain, impaired sleep, impaired glucose regulation, hypertension) and infant (e.g., earlier gestational age at birth, macrosomia [>4,000 grams]) health outcomes. Pregnant women are more sedentary than the average U.S. reproductive age woman (>12 hours/day vs. \<8 hours/day), placing pregnant women in the highest sedentary risk category. Most pregnant women do not meet pregnancy guideline recommendations for moderate-intensity PA of 150 minutes/week. Improved PA among pregnant women is crucial to improve maternal health outcomes.
Using a behavioral clinical trial design, 60 pregnant women with singleton pregnancy (e.g., no twins) will be recruited at 8-15 weeks, 6 days gestation (T1) from prenatal clinics. Participants will engage in the Sit Less, Move More (SLMM) intervention. At T1, participants complete questionnaires about SB and PA habits, weekly PA, and personal factors (e.g., demographics) and wear an ActiGraph PA tracker for 2 weeks. At Week 3, Fitbits and a SB and PA prescription will be given to participants with information on safe recommended pregnancy PA and health risks of SB while pregnant; have PA coaching (virtual 1:1 session, weekly texts); exercise with a partner at least 4 days/week; and receive Fitbit prompts for activity when SB ≥50 minutes while awake is detected. Participants also: 1) complete questionnaires at T2 (18-26 weeks) and T3 (28-36 weeks); and 2) wear a Fitbit throughout the study from Study Week 3 to 36 weeks gestation. We aim to: Aim 1) Determine the feasibility of recruitment, retention, adherence and acceptability of the SLMM intervention for pregnant women; and Aim 2) Obtain estimates of the efficacy of the SLMM intervention on daily SB, SB habit reversal, and weekly PA and PA habit for pregnant women.
The study will allow the investigators to modify SLMM, estimate its behavior change efficacy and lead to formal efficacy testing with an R01 submission to better understand pathways to improve SB and PA amongst pregnant women. This study fosters the NICHD mission to improve reproductive health and support enhanced maternal health and birth outcomes.
1,273 studies on the registry are indexed under Sedentary Behavior; 300 are open to participants now.
This study's planned enrollment of 60 is close to the median of 60 across 1,076 interventional studies indexed under Sedentary Behavior.
Browse Sedentary Behavior studies →University of Central Florida is the lead sponsor of 104 studies on the registry; 42 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Eligibility Criteria
Exclusion Criteria
Health Coaching sessions and text messages; Fitbit sedentary time disruption, monitoring, self-regulation, exercise with a partner most days of the week to ACOG opinion 804 recommended physical activity
Behavioral: Sit Less, Move More (SLMM) for pregnant women
Health Coach sessions and SMS texts ramp up to goal ACOG opinion 804 pregnancy physical activity; wearable device activity tracker (Fitbit) for monitoring and self-regulation, exercise with a partner for support and accountability most days of the week.
Change from first two weeks (baseline) ActiGraph device measured weekly moderate-intensity physical activity in minutes/week and time spent in sedentary behavior in hours per day
Change from first two weeks moderate-intensity physical activity in minutes per week and sedentary time measures in hours per day, baseline measure by participant blinded ActiGraph at 8 to 15 weeks, 6 days gestation, prior to the intervention beginning with goal of pregnancy recommended moderate-intensity physical activity using CDC talk test of 150 minutes/week measured by Fitbit and sedentary time 8 hours/day or less. The intervention begins at 10 to 18 weeks gestation. ActiGraph device measured change from 8 to 15 weeks, 6 days baseline physical activity and sedentary time as described above is measured again at 20 to 26 weeks gestation, and 30 to 36 weeks gestation in minutes of moderate-intensity physical activity per week and hours of sedentary time per day.
Time frame: Intervention begins at 10-15 weeks, 6 days gestation; 18-26 weeks gestation ActiGraph measured weekly PA & ST; 28 -36 weeks gestation ActiGraph measured weekly PA & ST; Fitbit measured weekly PA & daily ST measured 10-14 to 28-36 weeks gestation
Feasibility of recruitment for the study
The following metrics are used to measure this outcome: • Over 12 months the research team will recruit 60 participants.
Time frame: 12 months (February 2026 through February 2027)
Feasibility of retention in the SLMM intervention
The following metric is used to measure this outcome: ≥70% of participants in SLMM will be retained through 28 to 36 weeks gestation
Time frame: 10 to 18 weeks gestation start of SLMM per participant through 28 to 36 weeks gestation
Feasibility of adherence to the SLMM intervention
≥70% of participants in SLMM will adhere by achieving moderate-intensity physical activity ≥4 days/week as measured by Fitbit; using the Fitbit ≥10 hours/day for ≥4 days/week as measured by Fitbit; responding to ≥50% of Fitbit prompts of haptic vibration and text to move ≥4 days/week as measured by Fitbit; achieving decreased sedentary behavior by Fitbit measure by endpoint of 28 to 32 weeks gestation compared to first week of Fitbit use at 10-14 weeks gestation; complete ≥2 of 3 coach sessions as documented on coach session checklist at 10-14 weeks gestation, 18 to 19 weeks gestation and 28 to 29 weeks gestation; and receive weekly coach texts with receipt recorded in UCF text message software from 10 to 14 weeks gestation through 28 to 32 weeks gestation
Time frame: 10-14 weeks gestation through 28 to 32 weeks gestation
Acceptability of the SLMM Intervention to participants
≥80% of participants in SLMM will indicate high program acceptance of all components of the intervention--coaching Fitbit use and exercise with a partner, through satisfaction items on surveys item "How satisfied are you with the SLMM program?" and open-ended question response to "How satisfied are you with the SLMM program?" following coaching sessions as recorded on coach session checklist
Time frame: 20 to 28 weeks gestation and 30 to 36 weeks gestation
Plan to share: Yes — DATA MANAGEMENT AND SHARING PLAN below and through OpenICPSR according to its terms and conditions. Following the study and initial publications, data will be shared per NIH - NICHD requirements. The de-identified data will be housed indefinitely in the OpenICPSR databank administered by the University of Michigan. Access occurs by open access to researchers of member organizations such as UCF and otherwise through approved requests for research purposes. All de-identified participant data will be stored. No PHI or identifiable participant data from this study is stored in OpenICPSR. Users are required to apply for access to restricted data. Additionally, non-members will be charged $825 to access the data (this includes the administrative fee to access data in the virtual data enclave) plus a $349 administrative fee for secure download." https://www.openicpsr.org/openicpsr/faqs Further details are available here: https://www.openicpsr.org/openicpsr/accessRD;jses
Supporting information: Study protocol, Statistical analysis plan, Informed consent form
Time frame: Data will be shared after publications and initial presentations, anticipated to be 1 year following the final data analysis 1/1/2029
Access criteria: All de-identified participant data will be stored. No PHI or identifiable participant data from this study is stored in OpenICPSR. Users are required to apply for access to restricted data. Additionally, non-members will be charged $825 to access the data (this includes the administrative fee to access data in the virtual data enclave) plus a $349 administrative fee for secure download." https://www.openicpsr.org/openicpsr/faqs Further details are available here: https://www.openicpsr.org/openicpsr/accessRD;jses
Data sharing details ↗ · www.openicpsr.org
No publications or documents are linked to this record.
Started Feb 2026 (actual). Primary completion is estimated for Aug 2027, 18 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 18 months is above 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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