Effects of Implementing Exercise Interventions in School Physical Education on Anxiety Symptoms: A Randomized Clinical Trial

ERCT Criteria Breakdown

• Level 1 Criteria

  • C

    Class-level RCT

    • Randomization was performed using classes as the sampling units, satisfying the class-level randomization requirement.
    • "We performed the randomization considering the classes as sampling units."
    • Relevant Quotes: 1) "Teachers who agreed to participate were notified that both they and their classes would be randomly allocated to one of the 4 study groups (IG-1, IG-2, IG-3, or CG)." (p. 2) 2) "We performed the randomization considering the classes as sampling units." (p. 2) 3) "The allocation process considered balance in terms of school year, group distribution, and campus, and it was performed by an independent researcher." (p. 2) 4) "In addition, because we allocated all groups to both schools, we need to consider the possibility of contamination among them." (p. 7) Detailed Analysis: Criterion C requires that randomization occur at the class level (or stronger), rather than assigning different treatments to students within the same class (unless a tutoring exception applies). The paper explicitly states that randomization used "classes as sampling units" and that teachers and their classes were allocated to groups, which indicates class-level assignment. The authors note contamination risk because multiple study groups exist within the same campuses, but this does not change the unit of randomization (classes). Criterion C is met because the study randomized at the class level ("classes as sampling units").
  • E

    Exam-based Assessment

    • Outcomes were measured using a self-report anxiety scale (GAD-7), not standardized exam-based educational assessments.
    • "The dependent variable was AS, assessed using the Generalized Anxiety Disorder-7 scale, developed by Spitzer et al25 and validated by Kroenke et al.26"
    • Relevant Quotes: 1) "The dependent variable was AS, assessed using the Generalized Anxiety Disorder-7 scale, developed by Spitzer et al25 and validated by Kroenke et al.26" (p. 3) 2) "The Generalized Anxiety Disorder-7 consists of 7 items evaluating how the individual has felt over the past 2 weeks." (p. 3) 3) "Initially, participants completed the questionnaires in the classroom." (p. 3) Detailed Analysis: Criterion E requires standardized exam-based assessments of educational outcomes (eg, state or national achievement tests). This study evaluates anxiety symptoms using the GAD-7, which is a validated mental health instrument, but it is not an educational exam and does not measure academic learning outcomes. Criterion E is not met because outcomes are measured with the GAD-7 questionnaire rather than standardized educational exams.
  • T

    Term Duration

    • Outcomes were measured about 12 weeks after intervention start, which is approximately a full academic term.
    • "The intervention protocols were administered over 12 weeks and included diaphragmatic breathing exercises (IG-1), aerobic and resistance exercises (IG-2), and cooperative sports activities (IG-3), along with a control group."
    • Relevant Quotes: 1) "The intervention protocols were administered over 12 weeks and included diaphragmatic breathing exercises (IG-1), aerobic and resistance exercises (IG-2), and cooperative sports activities (IG-3), along with a control group." (p. 1) 2) "This study was a 4-arm, parallel-group randomized controlled trial conducted between February and July 2023." (p. 2) 3) "Preintervention assessments were conducted 1 week before the start of the intervention, and postintervention assessments were conducted during the week following the completion of the intervention." (p. 3) Detailed Analysis: Criterion T requires outcomes be measured at least one academic term after the intervention begins (typically ~3 months or more). The paper clearly states the intervention lasted 12 weeks, and postintervention assessments occurred in the week following completion, implying roughly 12–13 weeks from intervention start to outcome measurement. A 12-week period is commonly used as a term-length unit in academic scheduling, and it falls within the ERCT guideline’s approximate 3–4 month term window. While the paper does not define the institution’s official term length, the documented follow-up from start to outcome measurement is consistent with a full term in many educational settings. Criterion T is met because outcomes were measured about 12–13 weeks after intervention start, which is approximately one academic term.
  • D

    Documented Control Group

    • The control condition is clearly described (standard PE curriculum) and baseline characteristics and group sizes are reported.
    • "Participants in the CG followed the standard PE curriculum as previously planned."
    • Relevant Quotes: 1) "The study involved 326 students (IG-1 = 94, IG-2 = 56, IG-3 = 91, control group = 85), 46.9% female, and aged 17.1 (2.0) years." (p. 1) 2) "Control Group Participants in the CG followed the standard PE curriculum as previously planned." (p. 3) 3) "During the study period, classes included a variety of sports such as indoor soccer, soccer, basketball, volleyball, handball, rugby, punchball, tchoukball, korfball, athletics, tennis, and table tennis, among others." (p. 3) 4) "Table 1 Baseline Characteristics of Participants According to the Control and Intervention Groups" (p. 5) Detailed Analysis: Criterion D requires that the control group be well-documented, including what they received and baseline characteristics. The paper describes the control group as following the standard PE curriculum and provides concrete examples of typical activities. It also reports group sizes and baseline characteristics (Table 1), allowing assessment of comparability at baseline. Criterion D is met because the control condition and baseline/group characteristics are clearly documented.

• Level 2 Criteria

  • S

    School-level RCT

    • Randomization was conducted at the class level within campuses, not by assigning entire schools/campuses to conditions.
    • "We performed the randomization considering the classes as sampling units."
    • Relevant Quotes: 1) "Participants were students enrolled in integrated technical high school programs at 2 campuses of the Federal Institute of Education, Science, and Technology of Southern Rio Grande do Sul (IFSul), Brazil." (p. 2) 2) "Both campuses were selected by convenience." (p. 2) 3) "We performed the randomization considering the classes as sampling units." (p. 2) 4) "In addition, because we allocated all groups to both schools, we need to consider the possibility of contamination among them." (p. 7) Detailed Analysis: Criterion S requires school-level (institution-level) randomization where whole schools/campuses are assigned to conditions. Here, the campuses were selected by convenience, and the unit of randomization is explicitly the class, with all groups present within both campuses. The stated contamination risk is consistent with having multiple groups inside the same institutions rather than institution-level assignment. Criterion S is not met because assignment occurred among classes within campuses rather than randomizing whole campuses.
  • I

    Independent Conduct

    • The paper does not clearly document that the evaluation was led by an independent third-party team separate from the intervention designers/managers.
    • "For quality control purposes, we held weekly meetings with the teachers who applied the intervention on the 3 IG throughout the entire intervention phase."
    • Relevant Quotes: 1) "Prior to implementation, teachers completed a 6-hour training session (3-h theoretical and 3-h practical) focused on the delivery of the intervention protocols during PE classes." (p. 2) 2) "Data were collected by a team of evaluators composed of undergraduate and graduate PE students, who completed a 3-hour theoretical and practical training session prior to the assessments." (p. 3) 3) "Blinding was implemented for the assessment team (questionnaires and anthropometric measurements), as well as for data entry and analysis." (p. 3) 4) "For quality control purposes, we held weekly meetings with the teachers who applied the intervention on the 3 IG throughout the entire intervention phase." (p. 3) 5) "In addition, during the intervention period, members of the research team randomly selected 4 PE classes from each IG to observe the implementation of the activities (without interference)." (p. 3) Detailed Analysis: Criterion I requires that the study be conducted independently from the intervention designers to reduce bias. The paper documents blinding for the assessment team and for data entry/analysis, which helps reduce bias. However, the study team also trained teachers, held weekly implementation-monitoring meetings, and conducted observations, indicating substantial involvement in implementation oversight. The evaluators are described as trained PE students rather than an external evaluation organization, and the paper does not clearly state that an independent third-party evaluator led the study. Criterion I is not met because the paper does not clearly document independent conduct by a third-party evaluation team.
  • Y

    Year Duration

    • Outcomes were measured after about 12 weeks, far short of 75% of an academic year.
    • "The intervention protocols were administered over 12 weeks and included diaphragmatic breathing exercises (IG-1), aerobic and resistance exercises (IG-2), and cooperative sports activities (IG-3), along with a control group."
    • Relevant Quotes: 1) "The intervention protocols were administered over 12 weeks and included diaphragmatic breathing exercises (IG-1), aerobic and resistance exercises (IG-2), and cooperative sports activities (IG-3), along with a control group." (p. 1) 2) "Preintervention assessments were conducted 1 week before the start of the intervention, and postintervention assessments were conducted during the week following the completion of the intervention." (p. 3) Detailed Analysis: Criterion Y requires outcome measurement at least 75% of an academic year after the intervention begins. The paper documents a 12-week intervention with immediate postintervention measurement, which is substantially shorter than a typical academic year. Criterion Y is not met because the outcome window is about 12–13 weeks rather than most of an academic year.
  • B

    Balanced Control Group

    • The interventions were delivered within regular PE lesson time (content substitution), so student instructional time appears comparable to control; extra teacher training/monitoring is part of implementing the intervention.
    • "This study assessed the effects of incorporating 3 different interventions into parts of physical education classes on anxiety symptoms (AS) in high school students."
    • Relevant Quotes: 1) "This study assessed the effects of incorporating 3 different interventions into parts of physical education classes on anxiety symptoms (AS) in high school students." (p. 1) 2) "The diaphragmatic breathing intervention was implemented during the final 15 minutes of each PE lesson." (p. 2) 3) "The aerobic and resistance exercise intervention was implemented immediately after the warm-up, lasting 15 minutes per session." (p. 2) 4) "Sessions lasted 20 minutes and were conducted during the main part of the PE lesson." (p. 3) 5) "Participants in the CG followed the standard PE curriculum as previously planned." (p. 3) 6) "Prior to implementation, teachers completed a 6-hour training session (3-h theoretical and 3-h practical) focused on the delivery of the intervention protocols during PE classes." (p. 2) 7) "For quality control purposes, we held weekly meetings with the teachers who applied the intervention on the 3 IG throughout the entire intervention phase." (p. 3) Detailed Analysis: Criterion B compares the nature, quantity, and quality of resources (time, materials, staff support) provided to intervention and control conditions, and asks whether the control provides a comparable substitute for the intervention’s inputs, unless the added resources are integral to what is being tested. Student time/resources: Each intervention is explicitly inserted into the existing PE lesson (15 minutes or 20 minutes), which indicates substitution of lesson content rather than additional instructional time beyond usual PE. The control group also continued PE under the standard curriculum, so total PE time for students appears comparable. Additional teacher resources: Intervention teachers received a 6-hour training and ongoing monitoring meetings. The paper does not describe equivalent training for control teachers; however, these supports are directly tied to delivering the intervention protocols as defined (ie, they are integral implementation components rather than an unrelated add-on intended to increase student time). Criterion B is met because intervention delivery occurs within standard PE time (content substitution), and the additional teacher supports are integral to implementing the intervention protocols.

• Level 3 Criteria

  • R

    Reproduced

    • No independent replication of this specific RCT by other authors was found.
    • Relevant Quotes: 1) (No statements about replication by an independent research team are present in the paper text provided.) Detailed Analysis: Criterion R requires independent replication of the specific study by a different research team in a different context, published in a peer-reviewed outlet. The paper was first published online on February 26, 2026 and does not report any independent replication. An internet search did not identify a peer-reviewed replication of this exact four-arm trial (same intervention set and design) by an independent author team. Criterion R is not met because no independent replication of this specific study was found.
  • A

    All-subject Exams

    • Because exam-based assessment (E) is not met, the all-subject standardized exam requirement (A) is also not met.
    • "The dependent variable was AS, assessed using the Generalized Anxiety Disorder-7 scale, developed by Spitzer et al25 and validated by Kroenke et al.26"
    • Relevant Quotes: 1) "The dependent variable was AS, assessed using the Generalized Anxiety Disorder-7 scale, developed by Spitzer et al25 and validated by Kroenke et al.26" (p. 3) Detailed Analysis: Criterion A requires standardized exam-based assessment across all main academic subjects, and it depends on Criterion E. This paper measures anxiety symptoms using a questionnaire scale rather than standardized academic exams in any subject. Criterion A is not met because the study does not use standardized academic exams (and Criterion E is not met).
  • G

    Graduation Tracking

    • The study did not track participants to graduation, and no follow- up publication reporting graduation tracking was found.
    • "Another limitation was the lack of follow-up for participants after the intervention, which prevented us from understanding the possible long-term effects."
    • Relevant Quotes: 1) "Another limitation was the lack of follow-up for participants after the intervention, which prevented us from understanding the possible long-term effects." (p. 7) 2) "Preintervention assessments were conducted 1 week before the start of the intervention, and postintervention assessments were conducted during the week following the completion of the intervention." (p. 3) Detailed Analysis: Criterion G requires tracking participants until graduation. The paper explicitly states there was no follow-up after the intervention and documents only a short pre/post measurement window around a 12-week program. An internet search for subsequent papers by the same author team reporting long-term tracking of this cohort to graduation did not identify any such follow-up publication. Criterion G is not met because the study reports no follow-up after the intervention and does not track students until graduation.
  • P

    Pre-Registered

    • The trial was registered under NCT05561192 before the reported study start date of February 1, 2023.
    • "The study was reported in accordance with the Consolidated Standards of Reporting Trials16 guidelines for randomized parallel- group trials and was registered at ClinicalTrials.gov (NCT05561192)."
    • Relevant Quotes: 1) "The study was reported in accordance with the Consolidated Standards of Reporting Trials16 guidelines for randomized parallel- group trials and was registered at ClinicalTrials.gov (NCT05561192)." (p. 2) 2) "This study was a 4-arm, parallel-group randomized controlled trial conducted between February and July 2023." (p. 2) 3) "O protocolo do estudo foi relatado conforme as recomendações do SPIRIT12, foi aprovado pelo Comitê de Ética em Pesquisa da Escola Superior de Educação Física da Universidade Federal de Pelotas (5.594.529) e está registrado na plataforma Clinical Trials sob o número NCT05561192." (Protocol paper, p. 1) 4) "Last updated: September 26, 2022" (CenterWatch listing for NCT05561192) 5) "Study Start date: February 01, 2023" (CenterWatch listing for NCT05561192) Detailed Analysis: Criterion P requires that the study protocol be registered before the study begins. The paper explicitly reports registration at ClinicalTrials.gov (NCT05561192). The protocol publication also states the protocol is registered under NCT05561192. While the paper text itself does not quote the ClinicalTrials.gov posting date, an external ClinicalTrials.gov- derived listing reports the record was updated on September 26, 2022 and lists the study start date as February 01, 2023, which indicates registry information existed prior to study start. Criterion P is met because the study is registered as NCT05561192, and available registry-derived dates indicate registration activity occurred before the study start date (February 01, 2023).