Primary Care Referrals to a Remotely Delivered Physical Activity Intervention for Latina Teens: Chicas Fuertes 2

This study will test a physical activity intervention for Latina teenagers. Investigators will recruit 200 Latina adolescents who are currently under-active to participate in this 12-month study. Participants will be referred to the study by their primary care provider. Half of the participants will be randomly selected for the Intervention group, and will receive an individual counseling session and access to a personalized website. These participants will also receive a Fitbit activity tracker to help with goal setting and monitoring, plus weekly text messages and access to the study Instagram account to remind participants to be physically active. Those assigned to the control group will receive the Fitbit activity tracker.

Study Overview

• Status: Enrolling by invitation
• Conditions: Physical Activity
• Intervention / Treatment: Behavioral: Multi-technology MVPA intervention

Detailed Description

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 study team will recruit adolescent (age 13-17) Latinas (N=200) who are currently under-active 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 Type: Interventional
• Enrollment (Estimated): 200
• Phase: Not Applicable

Contacts and Locations

Study Locations

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

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• self identify as Latina
• age 13-17
• read, write, and speak English
• be a current patient at FHCSD
• be under-active (engaging in 60 min/day of MVPA on fewer than 5 days per week)
• regular access (≥2 times/week) to Internet and a smart phone that can receive text messages

Exclusion Criteria:

• unwillingness to be randomized to one of the two conditions
• self-reporting any condition that would impair ability to participate in physical activity for at least 10 minutes at a time

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Intervention; Participants 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.	Behavioral: Multi-technology MVPA intervention; Participants 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.
No Intervention: Control; Participants will receive a physical activity tracker (Fitbit) only.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Meeting guidelines for physical activity	Proportion of participants meeting guidelines of 60 min/day of moderate to vigorous physical activity (MVPA) measured by Fitbits	6 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Processes of Change for Physical Activity (POC)	Questionnaire that tracks cognitive and behavioral processes related to MVPA change	12 months
Stages of Change for Physical Activity (SCPA)	Questionnaire that determines what stage of exercise engagement the participant is currently in (precontemplation, contemplation, preparation, action, maintenance), and is used to stage-match treatment.	12 months
Self-Efficacy for Physical Activity (SE)	Questionnaire that measures self-efficacy to become physically active across diverse contexts	12 months
Social Support for Exercise (SSE)	Questionnaire measuring social support specifically in relation to exercise with three subscales (friends, family, rewards/punishments)	12 months
Outcome Expectations Scale	Questionnaire that measures the beliefs regarding the consequences of physical activity participation	12 months
Technology Engagment	Tracks activity on the study website (logins, goal setting, questionnaires answered), Fitbit activity (days worn, sync frequency), texting activity (% of interactive texts responded to), Instagram activity (views, likes)	12 months
Neighborhood Environment Walkability Scale for Youth (NEWS-Y)	Questionnaire that measures perceptions of neighborhood environment including recreation facility availability, pedestrian traffic safety, and walking facilities	Baseline
Vital Signs	Height, weight, resting blood pressure	12 months
Perceived Stress Scale (PSS)	Questionnaire used to assess stress levels	12 months
Demographics	Age, race, parent education and income, marital status, acculturation	Baseline
Physical Activity Enjoyment Scale (PACES)	Questionnaire that assesses level of personal satisfaction from physical activity	12 months
Maintenance of MVPA	Proportion of participants meeting guidelines of 60 minutes/day of MVPA measured by Fitbits.	12 months
Patient Health Questionnaire for Adolescents (PHQ A)	Questionnaire that assesses the degree of depression severity. Scores range from 0 to 27, with higher scores indicating more severe symptoms.	12 months
Dysmorphic Concern Questionnaire (DCQ)	Measures a person's degree of body image concern. Scores range from 0 to 21, with higher scores indicating greater preoccupation/anxiety with physical appearance.	12 months

Collaborators and Investigators

• Sponsor: University of California, San Diego
• Collaborators: National Heart, Lung, and Blood Institute (NHLBI); Family Health Centers of San Diego

Publications and helpful links

General Publications

• Larsen B, Greenstadt ED, Olesen BL, Marcus BH, Godino J, Zive MM. An mHealth Physical Activity Intervention for Latina Adolescents: Iterative Design of the Chicas Fuertes Study. JMIR Form Res. 2021 Jun 15;5(6):e26195. doi: 10.2196/26195.

Study record dates

Study Major Dates

• Study Start (Actual): April 10, 2025
• Primary Completion (Estimated): December 31, 2028
• Study Completion (Estimated): June 30, 2029

Study Registration Dates

• First Submitted: September 6, 2024
• First Submitted That Met QC Criteria: September 10, 2024
• First Posted (Actual): September 19, 2024

Study Record Updates

• Last Update Posted (Actual): May 26, 2026
• Last Update Submitted That Met QC Criteria: May 20, 2026
• Last Verified: May 1, 2025

More Information

Terms related to this study

• Keywords: mHealth; Latina; teenager; adolescent health; fitness tracker
• Additional Relevant MeSH Terms: Behavior; Motor Activity
• Other Study ID Numbers: 810268; R01HL171807 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: All quantitative data produced in the course of the project will be preserved and shared. Transcripts from stakeholder interviews will be shared only in the event that they give permission for the entire transcript to be shared; otherwise, summaries and codebooks will be shared.
• IPD Sharing Time Frame: Shared data generated from this project will be made available as soon as possible, and no later than the time of publication or the end of the funding period, whichever comes first. The duration of preservation and sharing of the data will be a minimum of 7 years after the end of the funding period.
• IPD Sharing Access Criteria: The Larsen USCD data provides metadata, persistent identifiers and long-term access. This repository is supported by USCD and dataset(s) are available through a request process directly with the PI, Dr. Larsen.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF; ANALYTIC_CODE; CSR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No