Physical Activity Intervention for Adolescent Girls

November 20, 2025 updated by: Britta Larsen, University of California, San Diego

Individually Tailored Physical Activity Intervention for Latina Adolescents: Chicas Fuertes

This study will conduct a randomized trial to evaluate the efficacy of a theory-based, individually tailored, multi-technology intervention on increasing physical activity in Latina adolescents, compared to a control group receiving only a physical activity tracker (a Fitbit). The investigators will recruit adolescent (age 13-18) Latinas (N=200) who are currently underactive to participate in the 12-month trial. Those randomized to the Intervention arm will receive a one-on-one counseling session and access to an individually tailored multi-media website. Key intervention components will be reinforced through text messaging to aid goal setting, a physical activity tracker (Fitbit) to set goals, track and log activity, and access to a study Instagram account to reinforce exposure to web content. The primary outcome will be increases in moderate-to-vigorous activity between baseline and 6 months. Secondary outcomes will include changes in activity at 12 months, potential mediators of the intervention, costs of delivering the intervention, behavior change trajectories from continuous data from Fitbits, potential moderators, and changes in physiological and psychological variables.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Latina adolescents report low levels of physical activity, with only 3% meeting national physical activity guidelines, and are at high lifetime risk for conditions related to inactivity, such as obesity, metabolic syndrome, and diabetes. Interventions grounded in sound psychosocial theory and leveraging growing technology use in Latina adolescents are needed to reverse patterns of inactivity, establish healthy lifetime habits and reduce widening disparities. The research team has developed and tested individually tailored, culturally adapted web-based interventions to increase moderate-to-vigorous physical activity (MVPA) for Latinos, which significantly increased MVPA in adult Latino men and women. In a recent pilot study (R03NR014329), this intervention was adapted based on formative interviews to make it appropriate for Latina adolescents and tested it in a single-arm pilot trial (N=21). After 12 weeks, retention was high (90.5%) and self-reported MVPA increased from 24.7(26.11) minutes/week at baseline to 79.4(46.8) at follow up (p<0.001), suggesting good potential efficacy. In closeout interviews, girls expressed a preference to increase audiovideo components of the website and to incorporate other mobile-health technologies, such as texting, smartphone apps, social media, and wearables. Thus, the aim of this study is to conduct a randomized controlled trial (N=200) of an individually tailored, theory-based, multi-technology intervention to increase MVPA in Latina adolescents. The intervention will comprise a counseling session to teach behavior change techniques, an interactive multimedia website with individually tailored content based on principles of the Transtheoretical Model and Social Cognitive Theory, a wearable tracker and smartphone app to reinforce key behavior change techniques, connection with a study Instagram account to reinforce exposure to intervention content, and automated text messages guide continued goal setting. Participants will be randomly assigned to receive the intervention or only a wearable tracker with smartphone app. Activity will be measured at baseline and six-month follow-up using well-established MVPA measures (accelerometers and the 7-Day Physical Activity Recall Interview). It is hypothesized that those randomized to receive the intervention will show significantly greater increases in MVPA at six months than those in the control group. The investigators will also evaluate whether changes in MVPA are mediated by changes in targeted psychosocial constructs (e.g. self-efficacy, social support) or engagement with technology, assess longer-term changes in MVPA at 12 months, and evaluate whether intervention effects are moderated by baseline personal and environmental variables (e.g. age, BMI, neighborhood environment). Costs to deliver the intervention (e.g. staff time, materials, overhead) will be tracked to evaluate costs and cost-effectiveness of both study arms, and the investigators will track contact time to assess whether staff contact is related to study outcomes. The investigators will also explore trajectories of daily activity in both the intervention and control groups using continuous data from wearable trackers. The proposed study will promote a critical preventive health behavior, physical activity, in Latina adolescents using technologies that are pervasive in this high risk, quickly growing population and highly scalable, laying the groundwork for cost-effective, broad reaching interventions with great potential for preventing chronic disease and promoting health and wellbeing throughout the lifespan.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
160

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • United States
    • California
      • La Jolla, California, United States, 92093
        • University of California, San Diego

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

13 years to 18 years (Child, Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • self identify as Latina
  • 13-18 years old
  • read, write, speak English
  • under active (participating in <150 minutes of moderate to vigorous physical activity per week)
  • regular access to the Internet (at least 2 times per week)
  • regular access to a cell phone that can send and receive text messages

Exclusion Criteria:

  • inability to safely engage in physical activity, as determined by the Physical Activity Readiness Questionnaire
  • BMI > 45
  • Plan to move from the area within 12 months

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Multi-technology physical activity intervention
Digital/social media
Behavioral: Digital/social media intervention
Participants will receive individual counseling, access to an individually tailored website, guided goal setting via texts, access to a study Instagram account, and a wearable tracker (Fitbit)
No Intervention: Control
Control group receives a Fitbit but none of the intervention components.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Objectively Measured Weekly Minutes of Activity
Time Frame: Baseline, 6 Months (MO)
The ActiGraph GT3X+ accelerometer will be the primary measure to assess objective changes in physical activity from baseline to 6 months. (waking hours only) to measure movement and intensity of activity
Baseline, 6 Months (MO)
Self-Reported Weekly Minutes of Activity
Time Frame: Baseline, 6 Months (MO)
The 7-Day Physical Activity Recall (PAR) will also assess self-reported changes in physical activity from baseline to 6 months. The 7-Day PAR is an interviewer administered instrument that uses multiple strategies for increasing accuracy of participant recall regarding many types of activities such as time spent sleeping and moderate, hard, and very hard intensity activities. The 7-Day PAR is used across many studies assessing physical activity and has consistently demonstrated acceptable reliability, internal consistency, and congruent validity with other objective measures of activity levels.
Baseline, 6 Months (MO)

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Objectively Measured Weekly Minutes Minutes of Activity
Time Frame: 12 months
weekly minutes of moderate-to-vigorous physical activity measured by ActiGraph accelerometer
12 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of California, San Diego

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
National Institute of Nursing Research (NINR)
Brown University

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Britta Larsen, PhD, UCSD

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
August 6, 2020

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
November 21, 2023

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
May 24, 2024

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
November 20, 2019

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
December 4, 2019

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
December 9, 2019

Study Record Updates

Last Update Posted (Estimated)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
December 9, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 20, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
November 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 182070
  • R01NR017876 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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