A Smartphone App to Improve Physical Activity

October 27, 2022 updated by: Stacey L. Schepens Niemiec, University of Southern California

A Smartphone Application to Improve Physical Activity in Underactive Older Adults

The purpose of this study is to develop, test, and optimize a physical activity (PA)-tracking smartphone app and specialty features, which are designed to facilitate older adults' PA by targeting common barriers in this population. For example, one feature sends messages throughout the day about the good things about growing older to combat negative views about aging which has been linked to decreased PA. Participants will include older adult smartphone users who are between the ages of 65 and 84 and are not very physically active. In phase one of the study, three groups of five older adults will be formed to test the PA-tracking app and one of three specialty features for a two-week period, followed by a focus group to learn about the older adults' experiences. In phase two, approximately 100 participants will be randomly assigned to one of eight groups that include various combinations of specialty features with the PA tracker, for the purpose of pilot testing the app for a four-month period. Testing will occur at the beginning and the end of the four-month intervention period, and will measure PA levels, sedentary activity time, self-reported PA, and functional mobility.

Study Overview

Detailed Description

In this study, we will optimize a set of tailored specialty app features designed to be paired with a physical activity (PA)-tracking app to boost older adults' PA. This package, termed the MovingUp suite, is distinct from generic fitness apps because it blends a set of specialized components that reflect empirically supported constructs from social cognitive and stereotype embodiment theory with evidence-based behavior change techniques (e.g., self-regulation) foundational to basic activity monitoring. Specialty features include: (a) explicit and implicit messaging to promote positive aging views; (b) sedentary activity monitoring with motivational messaging and peer suggestions; and (c) tailored messaging to increase the intensity level of everyday activities and overcome barriers. We will utilize a highly efficient, innovative methodological approach-Multiphase Optimization Strategy (MOST)-to provide an experimental context for evaluating the viability of each MovingUp specialty feature.

Aim 1: Assess the feasibility and acceptability of the three MovingUp specialty features. We will first examine MovingUp's feasibility and acceptability in three groups of five older adults (aged 65-84 years). A basic PA-tracking app plus one of three specialty features will be introduced-a different feature per group-at an orientation session. Groups will then test their assigned specialty feature with the PA tracker for two weeks. This step will involve real-time user data collection, check-ins via phone, and follow-up focus groups. Feasibility and acceptability will be determined by analyzing participants' usage patterns, evaluations of MovingUp features (based on a health technology usability scale and focus group interviews), and self-reported facilitators and barriers to successful app use. Our team will review the data and integrate changes as needed, producing an upgraded prototype to be assessed in Aim 2.

Aim 2: Conduct a pilot test to examine performance characteristics and PA-relevant outcomes of MovingUp's specialty features. Aim 2 includes the MOST Screening Phase: theory-guided experimentation to identify viable components within a multifaceted preliminary intervention plan. Using a factorial design as specified in MOST procedures, 100 underactive older adults (i.e., accumulating <150 minutes of moderate intensity activity per week) will be randomly assigned to one of eight conditions which reflect all possible combinations of presence vs. absence of the three respective specialty features, given usage of a PA tracker app. At the end of a four-month intervention period, for each specialty feature we will examine changes from baseline in PA-related outcomes including: objective PA (primary outcome), sedentary activity time, self-reported PA, and functional mobility. We will also examine the app components' relationships to theoretically postulated mediating constructs (self-efficacy, self-regulation, outcome expectation, social support, aging self-perception, and views of aging). In addition, we will document usage rate, sustained usage, and perceived usefulness for achieving PA goals for each suite component.

Aim 3: Synthesize information from Aim 2 to design an optimized MovingUp suite to be evaluated in a future RCT. Our study team will interpret and synthesize the array of resulting data to derive an optimized MovingUp suite. A set of pre-specified criteria will be used to guide selection of components in the optimized app. Using preliminary efficacy data, the stage will be set for a fully powered RCT of MovingUp's beneficial effects in comparison to alternate technologies such as web-based or mHealth solutions.

This project will help establish a methodological foundation for future attempts to enhance PA apps via the addition of theoretically based component features. Moreover, it will provide insights into the theoretical underpinnings of successful PA interventions for older adults, leading to information that transcends any single technology-based solution.

Study Type

Interventional

Enrollment (Actual)

111

Phase

  • 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 Locations

    • California
      • Glendale, California, United States, 91203
        • Front Porch Center for Innovation and Wellbeing
      • Los Angeles, California, United States, 90089-9003
        • University of Southern California

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

Ages Eligible for Study

65 years to 84 years (Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • 65-84 years old
  • English speaking
  • reside in Los Angeles
  • score ≥5 on a 6-item cognitive screener
  • report <150 minutes of moderate to vigorous PA/week as per a single-item screener
  • ambulatory
  • able to safely participate in physical activity as determined by the Revised Physical Activity Readiness Questionnaire (rPARQ) or proof of medical clearance from a physician
  • smartphone owner for ≥3 months
  • observed ability to reliably access and operate a smartphone during orientation.

Exclusion Criteria:

  • ≥85 years old, based on limited smartphone ownership and to reduce sample variability

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: Other
  • Allocation: Randomized
  • Interventional Model: Factorial Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Other: PA App+ On Your Feet+ CoachMe+ Proof Pos
Participants in this arm will use a basic physical activity (PA) tracker app in conjunction with the following 3 features: (1) "On Your Feet" (sedentary activity monitoring with motivational messaging and peer suggestions); (2) "Coach Me" (tailored messaging to increase the intensity level of everyday activities and overcome barriers); and (3) "Proof Positive" (explicit and implicit messaging to promote positive aging views).
This PA tracker app auto-monitors PA and provides a text-based summary of goal progress, thereby targeting self-regulation and outcome expectation.
On Your Feet is a specialty app feature designed to be paired with a PA tracker app and reduce sedentary activity-a health risk factor largely independent of insufficient PA. This feature utilizes self-regulatory and behavior change techniques including goal-setting, progress feedback, and prompting. Accumulated sedentary activity time is displayed alongside self-selected goals; reminders to stand are sent at a user-specified frequency; and general tips and previously compiled, older adult-identified strategies to reduce sedentary activity are texted. Additionally, messages about the benefits of reducing sedentary activity and overcoming barriers are sent.
Coach Me is a specialty app feature designed to be paired with a PA tracker app and includes daily messages that assist older adults in discovering practical ways to integrate PA into their daily routines and overcoming PA barriers. Blending PA with productive activity facilitates PA engagement in older adults. In Coach Me, suggestions on how to intensify daily activities are tailored based on user selections from an activity inventory. This app feature helps older adults become more active in a minimally intrusive way, while allowing for engagement in productive and meaningful activities. Coach Me asks users to select obstacles to PA encountered in the previous week. Based on those selections, the app sends strategies on how to overcome those barriers, thereby targeting self-efficacy.
Proof Positive is a specialty app feature designed to be paired with a PA tracker app and capitalizes on the beneficial effects that exposure to positive aging messages and stereotypes has on health and PA. When activated, users (a) receive texts describing how old age does not equate to physical inability, (b) obtain information about the benefits of growing older, and (c) are presented with a weekly positive aging stereotype task modeled after a computerized series. This last function exposes users to blocks of "positive priming words." Primers are quickly flashed to allow perception without awareness while users focus on a simple icon that represents PA. Icons are intended to provide an additional PA cue, maintain user interest, and increase the external validity.
Other: PA App + On Your Feet + Coach Me
Participants in this arm will use a basic physical activity (PA) app in conjunction with the following 2 features: (1) "On Your Feet" (sedentary activity monitoring with motivational messaging and peer suggestions); and (2) "Coach Me" (tailored messaging to increase the intensity level of everyday activities and overcome barriers).
This PA tracker app auto-monitors PA and provides a text-based summary of goal progress, thereby targeting self-regulation and outcome expectation.
On Your Feet is a specialty app feature designed to be paired with a PA tracker app and reduce sedentary activity-a health risk factor largely independent of insufficient PA. This feature utilizes self-regulatory and behavior change techniques including goal-setting, progress feedback, and prompting. Accumulated sedentary activity time is displayed alongside self-selected goals; reminders to stand are sent at a user-specified frequency; and general tips and previously compiled, older adult-identified strategies to reduce sedentary activity are texted. Additionally, messages about the benefits of reducing sedentary activity and overcoming barriers are sent.
Coach Me is a specialty app feature designed to be paired with a PA tracker app and includes daily messages that assist older adults in discovering practical ways to integrate PA into their daily routines and overcoming PA barriers. Blending PA with productive activity facilitates PA engagement in older adults. In Coach Me, suggestions on how to intensify daily activities are tailored based on user selections from an activity inventory. This app feature helps older adults become more active in a minimally intrusive way, while allowing for engagement in productive and meaningful activities. Coach Me asks users to select obstacles to PA encountered in the previous week. Based on those selections, the app sends strategies on how to overcome those barriers, thereby targeting self-efficacy.
Other: PA App + On Your Feet + Proof Positive
Participants in this arm will use a basic physical activity (PA) tracker app in conjunction with the following 2 features: (1) "On Your Feet" (sedentary activity monitoring with motivational messaging and peer suggestions); and (2) "Proof Positive" (explicit and implicit messaging to promote positive aging views).
This PA tracker app auto-monitors PA and provides a text-based summary of goal progress, thereby targeting self-regulation and outcome expectation.
On Your Feet is a specialty app feature designed to be paired with a PA tracker app and reduce sedentary activity-a health risk factor largely independent of insufficient PA. This feature utilizes self-regulatory and behavior change techniques including goal-setting, progress feedback, and prompting. Accumulated sedentary activity time is displayed alongside self-selected goals; reminders to stand are sent at a user-specified frequency; and general tips and previously compiled, older adult-identified strategies to reduce sedentary activity are texted. Additionally, messages about the benefits of reducing sedentary activity and overcoming barriers are sent.
Proof Positive is a specialty app feature designed to be paired with a PA tracker app and capitalizes on the beneficial effects that exposure to positive aging messages and stereotypes has on health and PA. When activated, users (a) receive texts describing how old age does not equate to physical inability, (b) obtain information about the benefits of growing older, and (c) are presented with a weekly positive aging stereotype task modeled after a computerized series. This last function exposes users to blocks of "positive priming words." Primers are quickly flashed to allow perception without awareness while users focus on a simple icon that represents PA. Icons are intended to provide an additional PA cue, maintain user interest, and increase the external validity.
Other: PA App + On Your Feet
Participants in this arm will use a basic physical activity (PA) tracker app in conjunction with the following feature: (1) "On Your Feet" (sedentary activity monitoring with motivational messaging and peer suggestions).
This PA tracker app auto-monitors PA and provides a text-based summary of goal progress, thereby targeting self-regulation and outcome expectation.
On Your Feet is a specialty app feature designed to be paired with a PA tracker app and reduce sedentary activity-a health risk factor largely independent of insufficient PA. This feature utilizes self-regulatory and behavior change techniques including goal-setting, progress feedback, and prompting. Accumulated sedentary activity time is displayed alongside self-selected goals; reminders to stand are sent at a user-specified frequency; and general tips and previously compiled, older adult-identified strategies to reduce sedentary activity are texted. Additionally, messages about the benefits of reducing sedentary activity and overcoming barriers are sent.
Other: PA App + Coach Me + Proof Positive
Participants in this arm will use a basic physical activity (PA) tracker app in conjunction with the following 2 features: (1) "Coach Me" (tailored messaging to increase the intensity level of everyday activities and overcome barriers); and (2) "Proof Positive" (explicit and implicit messaging to promote positive aging views).
This PA tracker app auto-monitors PA and provides a text-based summary of goal progress, thereby targeting self-regulation and outcome expectation.
Coach Me is a specialty app feature designed to be paired with a PA tracker app and includes daily messages that assist older adults in discovering practical ways to integrate PA into their daily routines and overcoming PA barriers. Blending PA with productive activity facilitates PA engagement in older adults. In Coach Me, suggestions on how to intensify daily activities are tailored based on user selections from an activity inventory. This app feature helps older adults become more active in a minimally intrusive way, while allowing for engagement in productive and meaningful activities. Coach Me asks users to select obstacles to PA encountered in the previous week. Based on those selections, the app sends strategies on how to overcome those barriers, thereby targeting self-efficacy.
Proof Positive is a specialty app feature designed to be paired with a PA tracker app and capitalizes on the beneficial effects that exposure to positive aging messages and stereotypes has on health and PA. When activated, users (a) receive texts describing how old age does not equate to physical inability, (b) obtain information about the benefits of growing older, and (c) are presented with a weekly positive aging stereotype task modeled after a computerized series. This last function exposes users to blocks of "positive priming words." Primers are quickly flashed to allow perception without awareness while users focus on a simple icon that represents PA. Icons are intended to provide an additional PA cue, maintain user interest, and increase the external validity.
Other: PA App + Coach Me
Participants in this arm will use a basic physical activity (PA) tracker app in conjunction with the following feature: (1) "Coach Me" (tailored messaging to increase the intensity level of everyday activities and overcome barriers).
This PA tracker app auto-monitors PA and provides a text-based summary of goal progress, thereby targeting self-regulation and outcome expectation.
Coach Me is a specialty app feature designed to be paired with a PA tracker app and includes daily messages that assist older adults in discovering practical ways to integrate PA into their daily routines and overcoming PA barriers. Blending PA with productive activity facilitates PA engagement in older adults. In Coach Me, suggestions on how to intensify daily activities are tailored based on user selections from an activity inventory. This app feature helps older adults become more active in a minimally intrusive way, while allowing for engagement in productive and meaningful activities. Coach Me asks users to select obstacles to PA encountered in the previous week. Based on those selections, the app sends strategies on how to overcome those barriers, thereby targeting self-efficacy.
Other: PA App + Proof Positive
Participants in this arm will use a basic physical activity (PA) tracker app in conjunction with the following feature: (1) "Proof Positive" (explicit and implicit messaging to promote positive aging views).
This PA tracker app auto-monitors PA and provides a text-based summary of goal progress, thereby targeting self-regulation and outcome expectation.
Proof Positive is a specialty app feature designed to be paired with a PA tracker app and capitalizes on the beneficial effects that exposure to positive aging messages and stereotypes has on health and PA. When activated, users (a) receive texts describing how old age does not equate to physical inability, (b) obtain information about the benefits of growing older, and (c) are presented with a weekly positive aging stereotype task modeled after a computerized series. This last function exposes users to blocks of "positive priming words." Primers are quickly flashed to allow perception without awareness while users focus on a simple icon that represents PA. Icons are intended to provide an additional PA cue, maintain user interest, and increase the external validity.
Other: PA App
Participants in this arm will use a basic physical activity (PA) tracker app without any additional features.
This PA tracker app auto-monitors PA and provides a text-based summary of goal progress, thereby targeting self-regulation and outcome expectation.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Daily Steps Change From Baseline to Month 4; Main Effect, and 2- and 3-way Interactions
Time Frame: 72-hour monitoring periods at Month 4 relative to baseline

Step counts (objective physical activity) were measured using the activPAL thigh-worn accelerometer during a 72-hour monitoring period.

Estimated average change is computed as the change in activPAL-tracked mean daily steps at Month 4 relative to baseline; this outcome is analyzed in a linear regression analysis model. All randomized participants who started the intervention and had valid activity monitor data were utilized in the model (ITT analysis)

72-hour monitoring periods at Month 4 relative to baseline

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Daily Sitting Time (activPAL) Change From Baseline to Month 4
Time Frame: 72-hour monitoring periods at Month 4 relative to baseline
Objective sedentary activity time was measured using the activPAL thigh-worn accelerometer during a 72-hour monitoring period. Expressed as average minutes/day.
72-hour monitoring periods at Month 4 relative to baseline
Self-reported Physical Activity (PASE) Change From Baseline to Month 4
Time Frame: baseline and 4 months
Self-reported physical activity will be measured via the Physical Activity Scale for the Elderly (PASE). PASE is a ten-item instrument designed to assess engagement in physical activities commonly pursued by older adults, including those related to leisure, household, and occupational tasks. The tool is a valid and reliable measure of physical activity engagement in the older adult population. Scores range from 0 to 361. Higher scores indicate a higher level of activity.
baseline and 4 months
Gait Speed (4-m Walk Test) Change From Baseline to Month 4
Time Frame: baseline and 4 months
Functional mobility will be assessed through a four-meter walk test, a commonly used, validated measure of physical and functional performance in older adults.
baseline and 4 months
Self-efficacy for Physical Activity (Health Beliefs Survey) Change From Baseline
Time Frame: baseline and 4 months
The potential mediators of physical activity self-efficacy, self-regulation, outcome expectation, and social support will each be measured separately using subscales of the 78-item physical activity portion of the Health Beliefs Survey. Subscales demonstrate sufficient internal consistencies (Cronbach's α=0.68-0.90) and are predictive of physical activity. Higher scores indicate greater self-efficacy. Possible scores for the self-efficacy subscale range from 0-100.
baseline and 4 months
Self-regulation of Physical Activity (Health Beliefs Survey Physical Activity Portion) Change From Baseline
Time Frame: baseline and 4 months
The potential mediators of physical activity self-efficacy, self-regulation, outcome expectation, and social support will each be measured separately using subscales of the 78-item physical activity portion of the Health Beliefs Survey. Subscales demonstrate sufficient internal consistencies (Cronbach's α=0.68-0.90) and are predictive of physical activity. Higher scores indicate greater self-regulation behaviors. Possible scores for the self-regulation subscale range from 1-5.
baseline and 4 months
Family Social Support for Physical Activity (Health Beliefs Survey Physical Activity Portion) Change From Baseline
Time Frame: baseline and 4 months
The potential mediators of physical activity self-efficacy, self-regulation, outcome expectation, and social support will each be measured separately using subscales of the 78-item physical activity portion of the Health Beliefs Survey. Subscales demonstrate sufficient internal consistencies (Cronbach's α=0.68-0.90) and are predictive of physical activity. Higher scores indicate greater family social support for physical activity. Possible scores for the family social support subscale range from 1 - 5.
baseline and 4 months
Outcome Expectation for Physical Activity (Health Beliefs Survey Physical Activity Portion) Change From Baseline
Time Frame: baseline and 4 months
The potential mediators of physical activity self-efficacy, self-regulation, outcome expectation, and social support will each be measured separately using subscales of the 78-item physical activity portion of the Health Beliefs Survey. Subscales demonstrate sufficient internal consistencies (Cronbach's α=0.68-0.90) and are predictive of physical activity. Higher scores indicate greater outcome expectations. Possible scores for the outcome expectation subscale range from 1-25
baseline and 4 months
Aging Self-perceptions (Attitudes Toward Own Aging) Change From Baseline
Time Frame: baseline and 4 months
Aging self-perceptions will be assessed by the Attitudes Toward Own Aging subscale of the Philadelphia Geriatrics Center Morale Scale. This five-question tool captures the subjective aging experience, shows moderate internal consistency (Cronbach's α=0.61-0.64), and predicts mortality risk. Scores can range from 0 to 5. A higher score indicates more positive aging self-perceptions.
baseline and 4 months
Views of Aging--Psychosocial Loss (Attitudes to Ageing Questionnaire) Change From Baseline
Time Frame: baseline and 4 months
Views of aging will be measured using the Attitudes to Ageing Questionnaire. This 24-item assessment identifies subjective views about age-related changes in multiple domains, is cross-culturally valid, and is psychometrically sound (Cronbach's α=0.68-0.84). Its subscales include psychosocial loss, physical change, and psychological growth. A higher score for psychosocial loss indicates more negative attitude (min 8; max 40).
baseline and 4 months
Views of Aging--Physical Change (Attitudes to Ageing Questionnaire) Change From Baseline
Time Frame: baseline and 4 months
Views of aging will be measured using the Attitudes to Ageing Questionnaire. This 24-item assessment identifies subjective views about age-related changes in multiple domains, is cross-culturally valid, and is psychometrically sound (Cronbach's α=0.68-0.84). Its subscales include psychosocial loss, physical change, and psychological growth. A higher score on physical change indicates more positive attitude (min 8; max 40)
baseline and 4 months
Views of Aging--Psychological Growth (Attitudes to Ageing Questionnaire) Change From Baseline
Time Frame: baseline and 4 months
Views of aging will be measured using the Attitudes to Ageing Questionnaire. This 24-item assessment identifies subjective views about age-related changes in multiple domains, is cross-culturally valid, and is psychometrically sound (Cronbach's α=0.68-0.84). Its subscales include psychosocial loss, physical change, and psychological growth. A higher score on psychological growth indicates more positive attitude (min 8; max 40).
baseline and 4 months
App Usage Behavior
Time Frame: from baseline through Month 4 (daily)
Usage behavior is defined as the proportion of days the app was opened across the 4-month trial period
from baseline through Month 4 (daily)
Perceived App Quality (uMARS)
Time Frame: 4 months
The Mobile App Rating Scale User Version (uMARS) was used to measure user satisfaction with the app, particularly participant's ratings for app quality. The uMARS includes a usability feedback subindex which is comprised of the average of item responses for 4 subsections (engagement, functionality, aesthetics, information), to yield a total quality score. Ratings are on a scale of 1 (low perceived quality, min) to 5 (high perceived quality, max).
4 months

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Correlation of Change in Daily Steps to Change in Hypothesized Mediators
Time Frame: baseline to Month 4 change
Spearman Correlation coefficients were calculated to assess correlations between change in the primary outcome (change in daily steps) and change in hypothesized mediators (i.e., Self-efficacy for Physical Activity Change, Self-regulation of Physical Activity Change, Family Social Support for Physical Activity Change, Outcome Expectation for Physical Activity Change, Aging Self-perceptions (Attitude Toward Own Aging) Change, Views of Aging--Psychosocial Loss Change, Views of Aging--Physical Change Change, Views of Aging--Psychological Growth Change).
baseline to Month 4 change

Collaborators and Investigators

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

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)

April 23, 2018

Primary Completion (Actual)

January 12, 2021

Study Completion (Actual)

January 12, 2021

Study Registration Dates

First Submitted

January 24, 2018

First Submitted That Met QC Criteria

January 24, 2018

First Posted (Actual)

January 31, 2018

Study Record Updates

Last Update Posted (Actual)

November 21, 2022

Last Update Submitted That Met QC Criteria

October 27, 2022

Last Verified

October 1, 2022

More Information

Terms related to this study

Other Study ID Numbers

  • HS-16-00670
  • R21AG052838 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

Yes

IPD Plan Description

This proposal does not involve a multisite trial. The University of Southern California is the only project site. Funds greater than $500,000 are not requested and thus data-sharing is not required. The final results and dataset of the project, however, will be published and shared according to the NIH regulations in order to improve the transparency of the research.

IPD Sharing Time Frame

Final results and dataset will be made available no later than the publication of the main findings from the final dataset. The data will remain in the repository indefinitely.

IPD Sharing Access Criteria

Persons accessing the data through the repository must agree to certain terms of use to include the following: (1) must use data for research purposes only and not for investigation of specific research subjects; (2) must make no use of the identity of any research subject discovered inadvertently, and to advise the repository of any such discovery; (3) must agree not to redistribute data or other materials without the written agreement; and (4) must reference the recommended bibliographic citation in any publication that employs resources provided by the repository. Authors of publications based on shared data are required to send citations of their published works to the repository for inclusion in a database of related publications.

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.

Clinical Trials on Sedentary Lifestyle

Clinical Trials on Physical Activity (PA) Tracker App

Subscribe