The Green Prescription Program for Increasing Physical Activity in Adolescents
Effectiveness of the Green Prescription: The Preventive Role of Health Education
1 other identifier
interventional
308
1 country
1
Brief Summary
This study evaluated the effectiveness of the Green Prescription, a school-based behavioral intervention that incorporated health education, designed to increase physical activity among adolescents aged 15-17 years who were insufficiently active. Participants received individualized written physical activity recommendations together with motivational support to encourage gradual increases in leisure-time physical activity. The intervention was tailored to three target groups: adolescents with overweight or obesity, excessive screen time, or low perceived social support. The study consisted of two sequential cohorts. In the first cohort, the Green Prescription was delivered by a physical education teacher. In the second cohort, the intervention was delivered by a physical education teacher supported by an interdisciplinary team consisting of a dietitian, psychologist, special education teacher, and physiotherapist. Physical activity and other health-related outcomes were assessed at baseline, immediately after the 12-week intervention, and six months later. The study evaluated the effectiveness of the Green Prescription in each intervention group and determined whether the interdisciplinary delivery model resulted in greater improvements in physical activity and healthy lifestyle behaviors than the teacher-led model.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P75+ for not_applicable
Started Jun 2024
Typical duration for not_applicable
1 active site
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
Study Start
First participant enrolled
June 3, 2024
CompletedPrimary Completion
Last participant's last visit for primary outcome
June 20, 2026
CompletedStudy Completion
Last participant's last visit for all outcomes
June 30, 2026
CompletedFirst Submitted
Initial submission to the registry
July 31, 2026
CompletedFirst Posted
Study publicly available on registry
August 18, 2026
CompletedAugust 18, 2026
July 1, 2026
2 years
July 31, 2026
August 13, 2026
Conditions
Keywords
Outcome Measures
Primary Outcomes (2)
Change in Moderate-to-Vigorous Physical Activity (MVPA) Screening Score
Self-reported physical activity was assessed using the MVPA screening measure. Participants reported the number of days on which they engaged in at least 60 minutes of moderate-to-vigorous physical activity (1) during the previous week (P1) and (2) during a typical week (P2). The MVPA screening score was calculated as the mean of the two responses: (P1 + P2) / 2, with a possible range of 0-7 days. Higher scores indicate a greater number of days with at least 60 minutes of MVPA.
Baseline, immediately after the 12-week intervention, and 6 months after completion of the intervention.
Change in Mean Daily Step Count (Huawei Watch Fit SE)
Objective physical activity assessed using Huawei Watch Fit SE. Participants wore the device for a 7-day baseline monitoring period, continuously throughout the 12-week intervention, for a 7-day post-intervention monitoring period, and for a 7-day monitoring period at the 6-month follow-up. The primary outcome is the mean daily step count derived from the monitoring periods used for outcome assessment.
Baseline, immediately after the 12-week intervention, and 6 months after completion of the intervention.
Secondary Outcomes (12)
Change in Body Mass Index (BMI)
Baseline, immediately after the 12-week intervention, and 6 months after completion of the intervention.
Change in Waist Circumference
Baseline, immediately after the 12-week intervention, and 6 months after completion of the intervention.
Change in Hip Circumference
Baseline, immediately after the 12-week intervention, and 6 months after completion of the intervention.
Change in Body Fat Percentage
Baseline, immediately after the 12-week intervention, and 6 months after completion of the intervention.
Change in Fat Mass
Baseline, immediately after the 12-week intervention, and 6 months after completion of the intervention.
- +7 more secondary outcomes
Study Arms (8)
OW - Teacher-Led Green Prescription
EXPERIMENTALAdolescents with insufficient physical activity and overweight or obesity participated in the first study cohort. Participants received the Green Prescription delivered by a physical education teacher. The intervention included individualized physical activity recommendations, motivational support, and educational materials focused on increasing physical activity and improving weight-related health behaviors.
HST - Teacher-Led Green Prescription
EXPERIMENTALAdolescents with insufficient physical activity and excessive screen time participated in the first study cohort. Participants received the Green Prescription delivered by a physical education teacher. The intervention included individualized physical activity recommendations, motivational support, and educational materials focused on increasing physical activity and reducing recreational screen time.
LSS - Teacher-Led Green Prescription
EXPERIMENTALAdolescents with insufficient physical activity and low perceived social support participated in the first study cohort. Participants received the Green Prescription delivered by a physical education teacher. The intervention included individualized physical activity recommendations, motivational support, and educational materials focused on increasing physical activity and strengthening social support for active lifestyles.
Comparison Group - Cohort 1
NO INTERVENTIONAdolescents with sufficient physical activity participated in the first study cohort. Participants completed the same assessments as the intervention groups but did not receive the Green Prescription intervention.
OW - Interdisciplinary Green Prescription
EXPERIMENTALAdolescents with insufficient physical activity and overweight or obesity participated in the second study cohort. Participants received the Green Prescription delivered by a physical education teacher with support from an interdisciplinary team consisting of a dietitian, psychologist, special education teacher, and physiotherapist. The intervention included individualized physical activity recommendations, motivational support, and educational materials focused on increasing physical activity and improving weight-related health behaviors.
HST - Interdisciplinary Green Prescription
EXPERIMENTALAdolescents with insufficient physical activity and excessive screen time participated in the second study cohort. Participants received the Green Prescription delivered by a physical education teacher with support from an interdisciplinary team consisting of a dietitian, psychologist, special education teacher, and physiotherapist. The intervention included individualized physical activity recommendations, motivational support, and educational materials focused on increasing physical activity and reducing recreational screen time.
LSS - Interdisciplinary Green Prescription
EXPERIMENTALAdolescents with insufficient physical activity and low perceived social support participated in the second study cohort. Participants received the Green Prescription delivered by a physical education teacher with support from an interdisciplinary team consisting of a dietitian, psychologist, special education teacher, and physiotherapist. The intervention included individualized physical activity recommendations, motivational support, and educational materials focused on increasing physical activity and strengthening social support for active lifestyles.
Comparison Group - Cohort 2
NO INTERVENTIONAdolescents with sufficient physical activity participated in the second study cohort. Participants completed the same assessments as the intervention groups but did not receive the Green Prescription intervention.
Interventions
The Green Prescription is a school-based behavioral intervention incorporating health education to promote leisure-time physical activity among adolescents with insufficient physical activity. The intervention includes individualized weekly written physical activity recommendations, educational materials, and weekly motivational support, supplemented by additional support when required, delivered by a physical education teacher over a 12-week period. All participants follow the same Green Prescription framework, with group-specific objectives, physical activity recommendations, and educational materials tailored to their primary risk profile (overweight or obesity, excessive recreational screen time, or low perceived social support). Activities were adapted to group needs and recommended PA levels. Written recommendations and educational materials were delivered electronically.
The Green Prescription is a school-based behavioral intervention incorporating health education to promote leisure-time physical activity among adolescents with insufficient physical activity. The intervention includes individualized weekly written physical activity recommendations, educational materials, and weekly motivational support, supplemented by additional support when required, over a 12-week period. The intervention is delivered by a physical education teacher together with an interdisciplinary team consisting of a dietitian, psychologist, special education teacher, and physiotherapist. All participants follow the same Green Prescription framework, with group-specific objectives, physical activity recommendations, and educational materials tailored to their primary risk profile (overweight or obesity, excessive screen time, or low perceived social support). Written recommendations and educational materials were delivered electronically.
Eligibility Criteria
You may qualify if:
- Adolescents aged 15-17 years.
- Enrollment in a participating secondary school.
- Health status allowing participation in physical activity.
- Stable body weight during the month preceding enrollment (±1 kg).
- Written informed consent from the participant and a parent or legal guardian, as required by local regulations.
- Intervention Groups (A-C)
- Participants were eligible if they met all of the following criteria:
- \- Insufficient physical activity, defined as reporting fewer than 5 days during the previous week with at least 60 minutes of moderate-to-vigorous physical activity, assessed using the MVPA questionnaire.
- and met one of the following group-specific criteria:
- Group A - Overweight or Obesity
- Body fat percentage above the age- and sex-specific reference values.
- BMI ≥25 kg/m² (used as an auxiliary screening criterion). Group B - High Screen Time
- Recreational screen time ≥4 hours per day. Group C - Low Social Support
- Low perceived social support assessed using the Student Social Support Scale for Young People (SSYSS).
- Low psychological well-being assessed using the KIDSCREEN-52 questionnaire (boys \<37.29; girls \<42.64).
- +3 more criteria
You may not qualify if:
- Secondary obesity.
- Acute or chronic medical conditions preventing participation in physical activity.
- Pregnancy or breastfeeding.
- Current psychological or psychiatric diagnosis requiring active treatment.
- Failure to provide written informed consent.
Contact the study team to confirm eligibility.
Sponsors & Collaborators
Study Sites (1)
Poznan University of Physical Education
Poznan, Greater Poland Voivodeship, 61-871, Poland
Related Publications (1)
Marlena Łopatka, Michał Bronikowski, Małgorzata Bronikowska, Agata Korcz, Maryna Khorkova, Dagny Adamczak, Jana Krzysztoszek; Physical activity recommendations for adolescents with overweight, high screen time, and low social support - A scoping review; Biomedical Human Kinetics; Volume 18 Issue 1; pp. 100-111. DOI: 10.2478/bhk-2026-0011
BACKGROUND
MeSH Terms
Conditions
Condition Hierarchy (Ancestors)
Study Officials
- PRINCIPAL INVESTIGATOR
Jana Krzysztoszek, PhD, DSc
Poznan University of Physical Education
Study Design
- Study Type
- interventional
- Phase
- not applicable
- Allocation
- NON RANDOMIZED
- Masking
- NONE
- Purpose
- PREVENTION
- Intervention Model
- PARALLEL
- Sponsor Type
- OTHER
- Responsible Party
- SPONSOR
Study Record Dates
First Submitted
July 31, 2026
First Posted
August 18, 2026
Study Start
June 3, 2024
Primary Completion
June 20, 2026
Study Completion
June 30, 2026
Last Updated
August 18, 2026
Record last verified: 2026-07
Data Sharing
- IPD Sharing
- Will not share
Individual participant data (IPD) will not be shared because the study involved minors, and no data-sharing plan was included in the study protocol or participant consent procedures.