https://orcid.org/0009-0001-6471-3646
Figures
Abstract
Background
China’s national school health policies face persistent implementation gaps, particularly in rural high schools prioritizing Gaokao. National surveys (2010–2019) documented alarming fitness declines: 50-m sprint speeds decreased (+0.3s boys; + 0.4s girls), pull-ups/sit-ups fell 29%/20%, and standing jumps shortened 6–7 cm.
Methods
A 16-week cluster quasi-experiment assigned intact rural high school classes (N = 98; age = 16.35 ± 0.48years) to: • Experimental (n = 50): Feature Recess-Time Sports Activities (FRTSA; 5x30-min/week). • Control (n = 48): Standard supervised running. Blinded assessors conducted the National Student Physical Health Standard tests.
Results
FRTSA elicited significant improvements versus control: • Speed: 50-m sprint (p < 0.001, η2 = 0.18, d = 0.75). • Explosive Power: Standing jump (p = 0.022, η2 = 0.05, d = 0.41). • Flexibility: Sit-and-reach (p < 0.001, η2 = 0.12, d = 0.60). • Strength: Male pull-ups (p = 0.030, d = 0.41); female sit-ups (p = 0.029, d = 0.45). No endurance benefits emerged (1000m/800m: all p > 0.05, d ≤ 0.18).
Citation: Huang XH, Huang XY, Rahman FA (2026) Feature recess-time sports activities as a school-based intervention to improve fitness in rural Chinese youth. PLoS One 21(1): e0337716. https://doi.org/10.1371/journal.pone.0337716
Editor: Rasool Abedanzadeh, Shahid Chamran University of Ahvaz, IRAN, ISLAMIC REPUBLIC OF
Received: June 22, 2025; Accepted: November 12, 2025; Published: January 22, 2026
Copyright: © 2026 Huang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Data Availability: Due to ethical restrictions involving minors and the sensitive nature of school-level fitness data in rural Chinese communities, the minimal dataset cannot be publicly archived. Researchers interested in accessing the data may submit a formal request to the Graduate School, Henan Normal University (yjsc@htu.edu.cn) or Xiayi Senior High School (xygzjdc@126.com), which serve as the institutional bodies responsible for research ethics oversight in this study. Requests will be jointly reviewed and must include: (1) a brief research proposal, (2) proof of institutional affiliation, and (3) a signed data use agreement ensuring confidentiality and ethical use. The corresponding author is not the sole point of contact for data access. Complete analysis scripts are available from the authors upon reasonable request.
Funding: The author(s) received no specific funding for this work.
Competing interests: The authors have declared that no competing interests exist.
Introduction
Physical fitness (PF) is a fundamental determinant of adolescent health [1,2], with adolescence constituting a critical window for establishing lifelong physical activity behaviors [3–5]. Robust evidence connects PF to: (a) cardiometabolic health indicators [6,7], (b) academic achievement [8], and (c) psychological well-being [9,10]. Although China’s Guidelines for Teaching Reform in Sports and Health (Trial) [11] emphasize youth health as a national priority, rural resource disparities – including physical education (PE) teacher shortages [12], equipment deficits [13], and inadequate facilities [14] – result in significantly lower PF levels among rural versus urban adolescents (p < 0.05) [15, 16].
To address these challenges, recess-time sports activities (RTSA) provide a promising, low-cost strategy to increase daily physical activity [17–20]. In this study, we introduce “Featured Recess-Time Sports Activities” (FRTSA)—a structured, theory-informed intervention designed to enhance engagement and fitness outcomes in resource-constrained settings. Unlike traditional RTSA, which is typically unstructured and student-led, FRTSA integrates guided instruction, progressive skill development, and music-paced routines to promote sustained moderate-to-vigorous physical activity (MVPA) [21].
The FRTSA model was developed using the ADDIE framework (Analysis, Design, Development, Implementation, Evaluation) to ensure systematic planning and iterative refinement [22]. It incorporates cooperative learning principles—emphasizing peer interaction, group goals, and shared responsibility—and scaffolding techniques, where activities are sequenced from basic to advanced with teacher support gradually reduced over time [23,24]. This theoretical foundation supports both motor skill acquisition and social-emotional development.
Building on China’s Sunshine Sports initiative (2007), FRTSA features: (1) scientific design (integrating PE guidelines and exercise physiology), (2) safety protocols (WHO-approved risk mitigation), (3) diversified modalities (≥1 activity type/session), and (4) adaptive flexibility (aligned with developmental needs and facility conditions) [25–27]. Although endorsed internationally [28,29], rural implementations face barriers such as spatial constraints (2.3 ± 0.8 m2/student vs. national ≥5.0 m2 standard) [30,31], equipment deficits [32], and organizational rigidity [33].
Current literature reveals two key gaps: (i) limited exploration of high school RTSA frameworks, and (ii) insufficient research on rural adolescent PF outcomes. To address these, we developed and tested an FRTSA model tailored for rural high schools. Using a dynamic distributed–concentrated approach, the model overcomes space and equipment limitations, offering a scalable solution for underserved populations.
The FRTSA program integrates four evidence-based components: (1) functional music gymnastics (coordination), (2) fun snake run (aerobic endurance), (3) figure skipping rope (gross motor skills), and (4) yoga-based relaxation (emotional regulation). Delivered over 16 weeks in a music-paced format (WHO standards, 2022) [34], FRTSA aims to optimize both physiological gains and student engagement during recess. This quasi-experimental study evaluated its efficacy in improving five PF domains: speed (50-m sprint), explosive power (standing long jump), flexibility (sit-and-reach), strength (pull-ups/sit-ups), and endurance (800/1000-m run). We hypothesized greater PF improvements in the experimental group (α = 0.05, two-tailed), providing an evidence-based strategy to reduce urban–rural fitness disparities through scalable school-based programming.
Materials and methods
Study design
Given the ethical constraints of randomizing intact school classes [35], we employed a two-arm quasi-experimental design to evaluate the feature recess-time sports activities (FRTSA) effects on physical fitness among rural Chinese high-school freshmen. The study protocol received ethical approval from Henan Normal University’s Institutional Review Board and strictly adhered to Belmont Report principles [36], with particular attention to: (1) respect for persons (written informed consent from all participants), (2) beneficence (risk-benefit analysis conducted prior to intervention), and (3) justice (equitable selection of participant schools).
While cluster randomization at the school level is considered optimal for minimizing contamination in school-based interventions, logistical and administrative constraints limited our ability to implement multi-school randomization. Instead, we conducted class-level randomization within a single school, which allowed for close supervision and consistent implementation while preserving classroom integrity. Sensitivity analyses were conducted to assess potential clustering effects, and intraclass correlation (ICC) was found to be low (< 0.05), suggesting minimal within-class dependency.
Study population and sampling
Paragraph 1: Sampling framework.
This study employed a multistage sampling approach to recruit high-school freshmen from Xiayi County, Henan Province, comprising: (1) stratified random selection of Henan from China’s 34 provincial divisions, (2) random selection of Shangqiu from Henan’s 17 prefecture-level cities, (3) random selection of Xiayi from Shangqiu’s six county-level districts, and (4) purposive selection of Xiayi County X High School (representative rural institution) from four local schools based on enrollment size and facility availability.
Paragraph 2: Participant recruitment.
Participants were composed of two randomly – selected Grade 1 classes (N = 98). All participants met the inclusion criteria:
- Age between 16 and 17 years
- No diagnosed physical impairments
- Obtained parental consent and student assent
The experimental group (n = 50; 26 males, 24 females; mean age = 16.4 ± 0.5 years) received FRTSA, whereas the control group (n = 48; 25 males, 23 females; mean age = 16.3 ± 0.5 years) continued with the standard RTSA. Baseline equivalence was confirmed for age (mean difference [MD] = 0.1 years, 95% confidence interval [CI]: [−0.2, 0.4], p = 0.76) and sex distribution (χ2 = 0.02, p = 0.92).
The two classes were selected based on comparable size, gender distribution, and baseline physical fitness levels. One class was assigned to the intervention group and the other to the control group through a random lottery draw conducted by an independent research coordinator. Given the school-based nature of the intervention and the need to preserve classroom integrity, students were not individually randomized but participated as intact class units. This approach balanced feasibility with methodological rigor in a real-world educational setting.
Paragraph 3: Sample size justification.
The sample size was determined using GPower 3.1. The following parameters were considered: a medium effect size (d = 0.5, as defined by Cohen in 1988), a significance level (α) of 0.05, and a statistical power of 0.80 [37]. Based on these specifications, the minimum required sample size (N) was calculated to be 92, with 46 participants per group. The final sample size, with N = 98, exceeded this calculated threshold, thus ensuring adequate statistical power for the study.
Intervention protocol
The 16-week intervention (September–December 2024) consisted of five 30-minute FRTSA sessions per week, integrating functional music gymnastics, fun snake run drills, structured figure skipping rope training, and guided yoga-based relaxation exercises. Pre- and post-intervention assessments were administered based on the China National Student Physical Fitness Standard (CNSPFS, 2014 revision) [38].
Outcome measurements
Anthropometric and physical fitness assessments were conducted before and after the 16-week intervention, following CNSPFS, 2014 revision (See S1 Appendix). Standardized tests included:
- Speed: 50-m sprint
- Explosive Power: Standing long jump
- Flexibility: Sit-and-reach test
- Strength: Pull-ups (males)/ 1-min sit-ups (females)
- Endurance: 1000-m run (males)/ 800-m run (females)
All measurements were conducted simultaneously for male and female students using CNSPFS-certified instruments (Table 1). Students in the experimental group completed their tests at the East Playground, while students in the control group were assessed at the West Playground. To minimize the impact of the endurance events (800-m and 1000-m runs) on subsequent tests, endurance assessments were scheduled on separate days. Except for the speed (50-m sprint) and endurance (800-m/1000-m run) tests, all other physical fitness tests were performed twice, with the best result recorded.
Although the total area of the East and West Playgrounds differed, the designated testing zones were comparable in surface material (poured rubberized concrete), flatness, and available space—all exceeding minimum requirements for each assessment. All tests were conducted outdoors on the same day and during the same time window (9:00–11:00 AM), under clear, windless conditions. No differences in lighting, temperature, or noise interference were observed between groups during testing.
Physical fitness assessment procedures
Body mass index test.
A portable high-precision anthropometric system (InBody BSM370, Korea) was used to assess biometric parameters. Participants stood barefoot on the measurement platform in a standardized anatomical position, ensuring heel alignment with the foot electrodes. After inputting age and gender data, the system automatically measured body weight (kg) and height (m) with medical-grade precision. Body mass index (BMI) was calculated instantly, and results were displayed on an LCD screen.
50-m sprint test.
The 50-m sprint test assessed speed performance using a racetrack, starting flag, whistle, and stopwatch. Participants, wearing sports attire, performed a standardized warm-up and assumed a ready stance behind the starting line. At the starter’s signal, they sprinted toward the finish line while the timekeeper recorded the completion time in seconds (s).
Standing long jump test.
The standing long jump test evaluated lower-limb explosive strength and coordination. Prior to testing, participants wore sports shoes and loose-fitting sportswear and completed warm-up exercises. During the test, participants stood with feet shoulder-width apart behind the take-off line, jumped forward with both feet simultaneously, and exited the landing area from the front after landing. Scoring was based on the position of the heels; if misaligned, the rear heel’s position was recorded. Each participant completed two trials, with the best score, measured in centimeters (cm), retained for analysis.
Sit-and-reach test.
The sit-and-reach test assessed flexibility, joint mobility, and muscle elasticity. Before testing, participants removed their shoes, wore loose sportswear, and positioned the measuring device against a wall with a soft mat in front. Participants sat with legs fully extended, heels together, toes approximately 30 degrees apart, and feet pressed against the device. With palms facing downward, they reached forward, pushing the sliding marker with their fingertips while maintaining straight knees and continuous contact between legs and mat. Scores were recorded based on the final vernier reading in centimeters (cm).
Pull-up test (male students).
Upper-body muscular strength and endurance were assessed using the Huake Zhichuang HK-PU01 intelligent pull-up tester. After a standardized warm-up, male participants grasped the horizontal bar with a shoulder-width overhand grip and fully extended arms. Upon activation of the device, participants performed pull-ups, ensuring that the chin cleared the bar for each valid repetition. The built-in sensors and AI recognition system automatically recorded valid counts and provided real-time feedback. Excessive body movement was prohibited, and a pause exceeding 10 seconds resulted in automatic test termination. Pull-up performance was measured in number of repetitions (count).
One-minute sit-up test (female students).
The one-minute sit-up test assessed abdominal and lumbar muscular endurance. Female participants, in pairs, completed the test, with one student stabilizing the ankles while the other performed sit-ups. Participants began in a supine position with hands interlocked behind the head, knees bent at 90°, and feet flat on the ground. On command, participants rose until their elbows touched their knees and returned to the starting position with shoulders contacting the mat. The total number of sit-ups completed in one minute was recorded. Proper breathing technique—exhaling during ascent and inhaling during descent—was required; breath-holding was prohibited.
1000-m/800-m Endurance test.
The 800-meter (female) and 1000-meter (male) run tests evaluated cardiovascular endurance. Participants wore sports attire and completed a standardized warm-up before testing. Students were grouped in sets of eight, and the course was marked by the teacher. Timing commenced at the start signal using a stopwatch, with participants adopting a staggered stance and maintaining rhythmic breathing patterns (e.g., inhaling every two to three steps). The final time, recorded in seconds (s), was documented upon crossing the finish line. Male students were tested first, followed by female students. After completing the test, participants engaged in cool-down exercises such as walking or light stretching to regulate breathing and were encouraged to hydrate.
Intervention program
The Feature Recess Time Sports Activities (FRTSA) intervention was implemented over 16 weeks, structured into four progressive stages. Weeks 1–4 (basic stage) emphasized the acquisition of fundamental movement skills. Weeks 5–8 (consolidation stage) focused on reinforcing and mastering these skills. Weeks 9–12 (improvement stage I) involved integrating all FRTSA components with musical accompaniment. Finally, weeks 13–16 (improvement stage II) aimed to refine movement proficiency and optimize overall performance. During the same period, the control group participated in a structured, military-style group running program implemented without musical accompaniment and directed by whistle cues from a physical education teacher. The session lasted 30 minutes daily and consisted of two phases: (1) Group Formation Running (25 min), during which students ran in square formations following standardized commands—initiated by a first whistle for double-time jogging and a second for quick-time walking, emphasizing rhythmic uniformity; and (2) Cool-Down and Dismissal (5 min), involving a silent, relaxed group walk followed by orderly return to the classroom led by a student monitor. This routine reflected the standard physical activity practice in many rural Chinese schools and served as the comparative baseline for evaluating the FRTSA intervention.
The FRTSA program incorporated functional music gymnastics, fun snake run, jump rope training, and yoga-based relaxation exercises. These components were designed to systematically enhance students’ flexibility, coordination, endurance, and overall physical fitness. The exercise components and the detailed implementation procedures are provided in Table 2.
Participant testing and data collection procedures
Two physical education teachers from Xiayi County Senior High School were first trained in the implementation of the intervention protocol. Subsequently, professional coaches from the Xiayi County Sports Education Bureau conducted standardized tests of participants’ height, weight, 50-meter sprint, pull-ups, 1-minute sit-ups, standing long jump, and sit-ups. The test results were immediately submitted to the research team for baseline evaluation. During the tests, the physical education teachers were responsible for maintaining order and ensuring the safety of the participants. They also led students through warm-up exercises before testing and guided them to each subsequent testing station.
Program relevance, engagement, and adherence monitoring
Perceived program relevance—reflecting students’ attitudes and motivation—was assessed in the FRTSA group using a 5-item survey at post-intervention. Items addressed enjoyment, perceived physical benefit, and willingness to continue, rated on a 5-point Likert scale (1 = strongly disagree, 5 = strongly agree). Internal consistency was acceptable (α = 0.76), and mean item scores were calculated for descriptive analysis.
Engagement and adherence were systematically monitored through daily attendance records and structured session logs maintained by physical education teachers. Adherence was defined as participation in ≥80% of scheduled sessions (≥ 64 out of 80 sessions over 16 weeks). Students attending fewer than 52 sessions (< 65%) were classified as low adherence and included in sensitivity analyses.
Instructional fidelity was ensured through a dual-layer monitoring system. All teachers received standardized training prior to implementation, covering procedural consistency and safety protocols. Weekly supervisory visits by research staff verified protocol adherence, and any deviations were documented in activity logs. This approach supported consistent delivery of both FRTSA and control conditions.
Statistical analysis
This study adhered to the CONSORT extension guidelines for non-randomized trials. Although the statistical analysis plan was developed a priori, it was not formally preregistered. All analyses were conducted using R version 4.3.2.
Baseline equivalence between the experimental and control groups was assessed using independent-samples t-tests for continuous variables and χ2 tests for categorical variables, with all comparisons yielding non-significant results (p > 0.05). Parametric assumptions were confirmed (Shapiro–Wilk test W > 0.95; Levene’s test p > 0.15). Within-group changes were analyzed using paired t-tests, and effect sizes were reported as Cohen’s d with 95% confidence intervals (CIs), classified as small (0.2–0.49), medium (0.5–0.79), and large (≥0.8).
Between-group differences were evaluated using analysis of covariance (ANCOVA) adjusting for baseline scores. To verify the assumption of homogeneity of regression slopes, we tested the interaction between group assignment and baseline fitness scores for each outcome. No significant interactions were observed (all p > 0.05), supporting the validity of the ANCOVA model. Results were presented as adjusted mean differences (ΔΔ) with 95% CIs, partial η2 values (interpreted as small ≥0.01, medium ≥0.06, large ≥0.14), and standardized mean differences. Analytical rigor was ensured through bootstrapped CIs (1,000 resamples), outlier screening (excluding <5% of cases), and Holm–Bonferroni corrections for multiple comparisons. All tests were two-tailed with a significance threshold set at α = 0.05. The study was powered (>80%) to detect medium-sized effects (d = 0.5). Complete analysis scripts are available from the authors upon reasonable request.
Results
Baseline equivalence between groups
Baseline characteristics were balanced between the experimental and control groups, with no statistically significant differences in age, sex, or BMI (p > 0.05; Table 3). Similarly, baseline performance across all physical fitness assessments showed no significant differences between groups (p > 0.05; Table 4). The effect sizes were trivial (Cohen’s d < 0.5), indicating minimal pre-intervention disparities.
Within-group effects of the intervention
Paired-sample t-tests were conducted to examine within-group differences before and after the intervention in both the experimental group (EG) and the control group (CG) (Table 5). In the 50-meter sprint, significant improvements were observed in both the CG (Δ = −0.17 s, 95% CI [−0.32, −0.02], p = 0.028, d = 0.21) and the EG (Δ = −0.79 s, 95% CI [−0.98, −0.60], p < 0.001, d = 0.98), with a notably larger effect size in the EG. Similar patterns were found in the standing long jump, where the CG improved by 13.20 cm (95% CI [7.32, 19.08], p < 0.001, d = 0.35), and the EG by 20.98 cm (95% CI [14.89, 27.07], p < 0.001, d = 0.56). In flexibility, assessed via the sit-and-reach test, the CG demonstrated a modest improvement (Δ = 1.41 cm, 95% CI [0.45, 2.37], p = 0.005, d = 0.27), whereas the EG exhibited a more pronounced gain (Δ = 4.55 cm, 95% CI [3.20, 5.90], p < 0.001, d = 0.82). Upper body strength in male students, measured by pull-ups, significantly increased in both groups (CG: Δ = 1.72 repetitions, 95% CI [0.85, 2.59], p < 0.001, d = 0.57; EG: Δ = 2.73 repetitions, 95% CI [1.80, 3.66], p < 0.001, d = 0.82). Among female students, abdominal muscle endurance, measured via 1-minute sit-ups, improved by 1.71 repetitions (95% CI [0.45, 2.97], p = 0.009, d = 0.27) in the CG and by 3.63 repetitions (95% CI [2.20, 5.06], p < 0.001, d = 0.55) in the EG. Cardiopulmonary endurance was significantly enhanced in both groups. Among male students, 1000-meter run times decreased significantly in the CG (Δ = −39.36 s, 95% CI [−47.20, −31.52], p < 0.001, d = 1.32) and the EG (Δ = −35.50 s, 95% CI [−42.30, −28.70], p < 0.001, d = 1.10). Similarly, female students in the CG improved their 800-meter run times by 18.38 seconds (95% CI [−25.20, −11.56], p < 0.001, d = 0.62), while those in the EG achieved a reduction of 22.53 seconds (95% CI [−27.30, −17.76], p < 0.001, d = 0.95). Collectively, these findings suggest that although both groups experienced improvements in physical fitness, the experimental group consistently exhibited greater magnitudes of change, indicating a stronger intervention effect.
Between-group effects of the intervention
After controlling for baseline scores using ANCOVA, significant between-group differences were observed in multiple physical fitness indicators (Table 6). Specifically, the experimental group (EG) exhibited greater improvements in 50-meter sprint performance compared to the control group (CG), with a mean difference of ΔΔ = –0.62 seconds, 95% CI [–0.85, –0.39], p < 0.001, partial η2 = 0.18, Cohen’s d = 0.75, indicating a large effect size. Similarly, EG demonstrated superior gains in standing long jump performance (ΔΔ = 7.78 cm, p = 0.022, η2 = 0.05, d = 0.41) and sit-and-reach flexibility (ΔΔ = 3.14 cm, p < 0.001, η2 = 0.12, d = 0.60), reflecting medium to large effects. Among male students, pull-up performance increased significantly in the EG (ΔΔ = 1.01 repetitions, p = 0.030, η2 = 0.05, d = 0.41), while among female students, significant improvements were observed in the 1-minute sit-up test (ΔΔ = 1.92 repetitions, p = 0.029, η2 = 0.06, d = 0.45). However, no statistically significant between-group differences were found in male students’ 1000-meter running times (ΔΔ = 3.86 seconds, p = 0.400, η2 = 0.01, d = 0.12) or female students’ 800-meter running times (ΔΔ = –4.15 seconds, p = 0.178, η2 = 0.03, d = 0.18). These findings suggest that the FRTSA intervention produced significant and meaningful improvements in students’ speed, power, flexibility, and muscular strength, particularly in short-duration, skill-related physical fitness domains.
While both the FRTSA and control groups demonstrated significant within-group improvements across all physical fitness domains—reflecting natural maturation, seasonal training effects, or routine physical activity—the magnitude and significance of gains differed meaningfully between groups. ANCOVA analyses revealed that the FRTSA intervention produced significantly greater improvements in speed (50m sprint), explosive power (standing long jump), flexibility (sit-and-reach), and muscular endurance (pull-ups/sit-ups), but not in aerobic endurance (1000-m/800-m run), highlighting its particular efficacy in skill- and strength-related physical fitness domains.
Discussion
This quasi-experimental study provides compelling evidence that a 16-week Feature Recess-Time Sports Activities (FRTSA) protocol significantly enhances multiple domains of physical fitness (PF) among rural Chinese high school students, outperforming traditional Recess-Time Sports Activities (RTSA). The findings support both initial hypotheses: (1) participants undergoing FRTSA demonstrated significant within-group improvements in PF measures, and (2) the FRTSA group (EG) achieved superior post-intervention outcomes compared to the control group (CG).
Our results revealed that students in the experimental group exhibited significantly greater improvements in short-term, skill-related fitness indicators—particularly 50-meter sprint time, standing long jump distance, sit-and-reach flexibility, and gender-specific muscular strength tests—relative to their peers in the control group. These between-group differences emerged after adjusting for baseline equivalence, as no significant differences were observed between groups at the pre-test.
The largest effect sizes were observed in the 50-meter sprint (Cohen’s d = 0.75) and sit-and-reach test (Cohen’s d = 0.60). These findings align with prior literature suggesting that repetitive exposure to functional, rhythmic activities such as rope skipping and structured gymnastics enhances neuromuscular coordination and lower-limb explosiveness [39–40]. Moreover, the yoga-based relaxation sessions, which emphasized static stretching and controlled breathing, likely contributed to the gains in flexibility. Such mind–body practices have increasingly been linked to improved joint range of motion and proprioceptive awareness in adolescents [41–42].
Moderate but statistically significant improvements were also observed in strength measures—pull-ups for males (Cohen’s d = 0.41) and 1-minute sit-ups for females (Cohen’s d = 0.45). These results reinforce the effectiveness of bodyweight-based, repetitive movement formats—particularly rope skipping and dynamic gymnastics—in developing muscular endurance during adolescence. These findings are in line with Rico-González [43], who emphasized that structured and playful strength-based activities are developmentally appropriate and efficacious in school-based physical education.
In contrast, the intervention did not produce statistically significant between-group differences in 1000-meter (males) and 800-meter (females) endurance runs. While the serpentine running activity was designed to enhance aerobic capacity, it may not have provided sufficient volume, intensity, or specificity to exceed the performance gains elicited by the traditional long-distance running adopted in the control condition. This may reflect the principle of specificity, as the CG’s intervention was more closely aligned with the task demands of the aerobic endurance assessments.
These findings suggest that while FRTSA is effective in improving components such as speed, strength, flexibility, and coordination, its current aerobic training component may require further development. Future iterations of the FRTSA model may benefit from integrating higher-intensity or longer-duration aerobic elements—such as interval running or circuit-based endurance drills—to better target cardiorespiratory fitness.
Overall, this study highlights the value of a multi-modal, scaffolded, and engaging physical activity framework—such as FRTSA—in enhancing adolescent physical fitness. Compared to the monotonous collective running utilized in the RTSA group, the diversity and structure of FRTSA activities may not only promote broader physical performance gains but also foster greater intrinsic motivation and participation adherence. These behavioral factors are essential for long-term physical activity engagement and health promotion in youth [21,44–46]. Future research should explore longitudinal follow-ups to assess whether the observed fitness improvements are sustained over time, as well as examine potential mediating effects of psychological outcomes (e.g., motivation, enjoyment) associated with the FRTSA model. Additionally, further refinement of the intervention’s aerobic component could enhance its comprehensiveness and impact.
A limitation of this study was that outcome assessors were not blinded to group allocation. Although standardized protocols and objective instruments (e.g., electronic timers) were used for key tests such as the 50-meter sprint and endurance runs, performance assessment for sit-ups and jump technique relied on direct observation, which may have introduced subtle measurement or performance biases. Future studies should consider involving independent evaluators or video-based scoring to minimize observer expectancy effects.
Additionally, several potential confounding factors—such as dietary intake, participation in extracurricular physical activities, and socioeconomic status—were not measured in this study. While randomization helps distribute such variables evenly across groups, residual confounding cannot be ruled out, particularly in rural settings where access to nutrition and out-of-school sports may vary significantly. These factors could influence baseline fitness levels and responsiveness to intervention.
The observed effects may also be shaped by behavioral and environmental mechanisms. The FRTSA program’s structured yet playful design likely enhanced intrinsic motivation and adherence compared to the repetitive, drill-based nature of the control group’ s military-style running. In rural Chinese schools, where extracurricular physical activity opportunities are often limited, the innovative and diversified structure of FRTSA may have provided a unique stimulus for engagement [47]. Furthermore, the integration of music, peer interaction, and progressive skill development aligns with self-determination theory, supporting autonomy, competence, and relatedness—key drivers of sustained physical activity in adolescents [45–46]. These psychosocial factors, while not directly measured, may partially explain the superior improvements in speed, strength, and flexibility observed in the intervention group.
Conclusions
In conclusion, FRTSA protocol demonstrates substantial potential as a developmentally appropriate, inclusive, and pedagogically grounded intervention for promoting multidimensional physical fitness among adolescents. Its capacity to elicit significant and clinically meaningful improvements—particularly in speed, explosive power, and flexibility—underscores its alignment with critical neuromotor development objectives during early adolescence. These findings support the integration of FRTSA into school-based physical activity programs as a feasible, scalable, and sustainable approach to enhancing health-related fitness outcomes. Future research should investigate the long-term sustainability of these benefits and examine the applicability and effectiveness of this model across diverse educational and demographic contexts.
Supporting information
S1 Appendix. Physical health measurement score.
https://doi.org/10.1371/journal.pone.0337716.s001
(DOCX)
References
- 1. Lema-Gómez L, Arango-Paternina CM, Eusse-López C, Petro J, Petro-Petro J, López-Sánchez M, et al. Family aspects, physical fitness, and physical activity associated with mental-health indicators in adolescents. BMC Public Health. 2021;21(1):2324. pmid:34969395
- 2. Sun H, Du C-R, Wei Z-F. Physical education and student well-being: Promoting health and fitness in schools. PLoS One. 2024;19(1):e0296817. pmid:38271399
- 3.
Conkle J. Physical best: Physical education for lifelong fitness and health. Human Kinetics. 2019.
- 4. van Sluijs EMF, Ekelund U, Crochemore-Silva I, Guthold R, Ha A, Lubans D, et al. Physical activity behaviours in adolescence: Current evidence and opportunities for intervention. Lancet. 2021;398(10298):429–42. pmid:34302767
- 5. Duff SV, Kimbel JD, Grant-Beuttler M, Sukal-Moulton T, Moreau NG, Friel KM. Lifelong fitness in ambulatory children and adolescents with cerebral palsy II: Influencing the trajectory. Behav Sci (Basel). 2023;13(6):504. pmid:37366756
- 6. Roldão da Silva P, Castilho Dos Santos G, Marcio da Silva J, Ferreira de Faria W, Gonçalves de Oliveira R, Stabelini Neto A. Health-related physical fitness indicators and clustered cardiometabolic risk factors in adolescents: A longitudinal study. J Exerc Sci Fit. 2020;18(3):162–7. pmid:32636893
- 7. Rao P, Belanger MJ, Robbins JM. Exercise, physical activity, and cardiometabolic health: insights into the prevention and treatment of cardiometabolic diseases. Cardiol Rev. 2022;30(4):167–78. pmid:34560712
- 8. Camacho-Morles J, Slemp GR, Pekrun R, Loderer K, Hou H, Oades LG. Activity Achievement emotions and academic performance: A meta-analysis. Educ Psychol Rev. 2021;33(3):1051–95.
- 9. Klussman K, Langer J, Nichols AL. The relationship between physical activity, health, and well-being. Eur J Health Psychol. 2021;28(2):59–70.
- 10. Wang K, Li Y, Zhang T, Luo J. The relationship among college students’ physical exercise, self-efficacy, emotional intelligence, and subjective well-being. Int J Environ Res Public Health. 2022;19(18):11596. pmid:36141869
- 11.
Ministry of Education of the People’s Republic of China. Guidelines for Teaching Reform in Sports and Health (Trial). 2021 [cited 2025 Apr 23].
- 12. Ellison DW, Woods AM. Physical education teacher resilience in high-poverty school environments. Eur Phys Educ Rev. 2018;25(4):1110–27.
- 13. Chaabane S, Chaabna K, Doraiswamy S, Mamtani R, Cheema S. Barriers and facilitators associated with physical activity in the middle East and North Africa Region: A systematic overview. Int J Environ Res Public Health. 2021;18(4):1647. pmid:33572229
- 14. Mncube DW, Ajani O A, Ngema T, Mkhasibe RG. Exploring the problems of limited school resources in rural schools and curriculum management. UMT Education Review. 2023; 6(2), 1–31. https://doi.org/10.32350/uer.62.01
- 15. Dong Y, Chen M, Song Y, Ma J, Lau PWC. Geographical Variation in physical fitness among chinese children and adolescents from 2005 to 2014. Front Public Health. 2021;9:694070. pmid:34540783
- 16. Jiang Q, Huang X, Cui D. Rural-urban differences in physical fitness and overweight prevalence of children and adolescents from central South China. Int J Environ Res Public Health. 2023;20(3):2390. pmid:36767757
- 17. Pulido Sánchez S, Iglesias Gallego D. Evidence-based overview of accelerometer-measured physical activity during school recess: An updated systematic review. Int J Environ Res Public Health. 2021;18(2):578. pmid:33445554
- 18. Massey WV, Thalken J, Szarabajko A, Neilson L, Geldhof J. Recess quality and social and behavioral health in elementary school students. J Sch Health. 2021;91(9):730–40. pmid:34235736
- 19. Hodges VC, Centeio EE, Morgan CF. The benefits of school recess: A systematic review. J Sch Health. 2022;92(10):959–967.
- 20. Ickes MJ, Erwin H, Beighle A. Systematic review of recess interventions to increase physical activity. J Phys Act Health. 2013;10(6):910–26. pmid:23074100
- 21. Kou R, Li Z, Li M, Zhou R, Zhu F, Ruan W, et al. Comparative effectiveness of physical exercise interventions on sociability and communication in children and adolescents with autism: A systematic review and network meta-analysis. BMC Psychol. 2024;12(1):712. pmid:39614353
- 22. Boke H, Aygun Y, Tufekci S, Yagin FH, Canpolat B, Norman G, et al. Effects of cooperative learning on students’ learning outcomes in physical education: A meta-analysis. Front Psychol. 2025;16:1508808. pmid:40432799
- 23. Dyson B, Casey A. Cooperative Learning in Physical Education and Physical Activity. Routledge. 2016.
- 24. Mesquita I, Farias C, De Martin Silva L, Afonso J, Coutinho P. How can learner-oriented scaffolding strategies be implemented in coach education? A case study. Res Q Exerc Sport. 2023;94(1):216–25. pmid:35323091
- 25.
Ministry of Education of the People’s Republic of China, General Administration of Sport of China, Communist Youth League Central Committee. Policy Document No. 6: Implementation Plan for Nationwide Sunshine Sports Campaign. Ministry of Education of the People’s Republic of China. 2007.
- 26. World Health Organization. WHO guidelines on physical activity and sedentary behaviour. World Health Organization. 2020. https://www.who.int/publications/i/item/9789240015128
- 27. Lonsdale C, Sanders T, Parker P, Noetel M, Hartwig T, Vasconcellos D, et al. Effect of a scalable school-based intervention on cardiorespiratory fitness in children: A cluster randomized clinical trial. JAMA Pediatr. 2021;175(7):680–8. pmid:33938946
- 28.
UNESCO. Quality physical education (QPE): Guidelines for policy-makers. UNESCO. 2015.
- 29.
UNESCO, WHO, UNICEF. Making every school a health-promoting school: global standards and indicators for health-promoting schools and systems. WHO and UNESCO. 2021.
- 30. Jiang B, Nordin J, Mohd Salleh MN. Design preferences for learning spaces among rural primary school students in China: A case study. Building Res Info. 2024;53(4):458–78.
- 31. Hassan AS, Witchayangkoon B. Articles in ITJEMAST 13 (5) 2022. Int Transaction J Eng Manag Appl Sci Technol. (2022)
- 32. Song J. The impact of economic development on inadequate education resources in rural China. EHSS. 2023;23:285–90.
- 33.
Kilty JL. School structure differences and physical activity of youth: A case study of four rural communities. University of Nebraska at Omaha. 2023.
- 34.
World Health Organization. Promoting physical activity through schools: policy brief. World Health Organization. 2022.
- 35. Troyer M. The gold standard for whom? Schools’ experiences participating in a randomised controlled trial. Journal Research in Reading. 2022;45(3):406–24.
- 36.
National Commission for the Protection of Human Subjects of Biomedical and Behavioral Research. The Belmont report: Ethical principles and guidelines for the protection of human subjects of research. Department of Health, Education, and Welfare, National Commission for the Protection of Human Subjects of Biomedical and Behavioral Research. 1978. https://www.hhs.gov/ohrp/regulations-and-policy/belmont-report/read-the-belmont-report/index.html
- 37.
Cohen J. Statistical power analysis for the behavioral sciences. 2nd ed. Lawrence Erlbaum Associates.
- 38.
Ministry of Education of the People’s Republic of China. (2014). Jiaoyubu guanyu yinfa “Guojia xuesheng tizhi jiankang biaozhun (2014nian xiuding)” de tongzhi [Notice of the Ministry of Education on the National Student Physical Fitness Standard (Revised 2014)]. Ministry of Education of the People’s Republic of China.
- 39. Russo L, Palermi S, Dhahbi W, Kalinski SD, Bragazzi NL, Padulo J. Selected components of physical fitness in rhythmic and artistic youth gymnast. Sport Sci Health. 2020;17(2):415–21.
- 40. Cabrejas C, Solana-Tramunt M, Morales J, Nieto A, Bofill A, Carballeira E, et al. The effects of an eight-week integrated functional core and plyometric training program on young rhythmic gymnasts’ explosive strength. Int J Environ Res Public Health. 2023;20(2):1041. pmid:36673798
- 41. Winter L, Huang Q, Sertic JVL, Konczak J. The effectiveness of proprioceptive training for improving motor performance and motor dysfunction: A systematic review. Front Rehabil Sci. 2022;3:830166. pmid:36188962
- 42. Cerdá A, Boned-Gómez S, Baena-Morales S. Exploring the mind-body connection: yoga, mindfulness, and mental well-being in adolescent physical education. Educ Sci. 2023;13(11):1104.
- 43. Rico-González M. The effect of primary school-based physical education programs: A systematic review of randomized controlled trials. J Phys Act Health. 2023;20(4):317–47. pmid:36870346
- 44. Moon J, Webster CA, Mulvey KL, Brian A, Stodden DF, Egan CA, et al. Physical activity interventions to increase children’s social and emotional learning: A systematic review and meta‐analysis based on the comprehensive school physical activity programme framework. Review of Education. 2024;12(1).
- 45. Rosenkranz RR, Ridley K, Guagliano JM, Rosenkranz SK. Physical activity capability, opportunity, motivation and behavior in youth settings: Theoretical framework to guide physical activity leader interventions. Int Rev Sport Exercise Psychol. 2021;16(1):529–53.
- 46. Lev-Arey D, Gutman T, Levental O. Empowering movement: Enhancing young adults’ physical activity through self-determination theory and acceptance and commitment therapy-based intervention. Behav Sci (Basel). 2024;14(2):130. pmid:38392483
- 47. Hussain AH, Samiulah M, Ahmad R, Asadullah. Effect of co-curricular activities on self confidence of elementary. Educ Res Innov. 2024;4(3):45–53.