Introduction

Primary school is a critical period in the physical and mental development of students, and the level of health at this time is not only the key to personal growth and success, but also closely related to the future of society1,2,3,4. However, the physical condition of primary school students is not optimistic, and their psychological problems are becoming increasingly serious5,6,7,8,9. Globally, it is estimated that one in seven (14 per cent) of people aged 10–19 suffer from a mental disorder. And these disorders remain largely unknown and untreated10,11. Despite significant improvements in child survival, nutrition and education in recent decades, progress on child health indicators across all the Sustainable Development Goals is currently at a standstill12. Studies have found that globally, more than 80 per cent of adolescents in school do not meet the currently recommended standard of at least one hour of physical activity per day13. Physical inactivity increases the risk of non-communicable diseases, poor physical and cognitive functioning, weight gain and mental illness14,15. Therefore, regular physical activity reduces the risk of non-communicable diseases, poor physical and cognitive functioning and mental illness. There are benefits for mental health and weight maintenance14,16,17.

In the primary education stage, the role of physical education (PE) teachers is crucial, not only as the transmitter of students’ physical education skills, but also as the guide of students’ physical and mental health development18,19. In recent years, more and more studies have begun to focus on the impact of PE teachers’ teaching styles on students’ physical and mental health20. Among them, PE teacher autonomy support has become a focus of much attention21. Teachers respect students in the teaching process, encourage students to participate actively and make their own choices, and provide necessary support and guidance22,23. When PE teacher autonomy support teaching methods, they encourage students to choose physical activities that suit their interests and abilities, and provide positive feedback and constructive guidance24. Therefore, the paper is based on the role of PE teacher autonomy support in promoting the physical and mental health of primary school students, with a view to effectively optimizing PE teaching and providing theoretical references for improving the physical and mental health of primary school students.

Literature review

Autonomy support is an important external environment widely advocated in self-determination theory, which is generally considered from the perspective of the person being supported25,26,27. Teacher autonomy support is a motivational style displayed by the teacher in performing classroom management by taking a student-centred view of the problem from the student’s perspective28. They give students the space to be autonomous, encourage them to come up with their own ideas, understand how they feel, give positive feedback on their classroom queries, and tend to focus on students’ independent thinking from the teacher’s perspective29,30. This helps them gradually learn to plan their exercise reasonably according to their physical condition and time schedule, and then develop long-term regular exercise habits, laying a solid foundation for physical health31,32. At the same time, primary school students can achieve more successful experiences in sports activities, thus enhancing their self-confidence33. This self-confidence will gradually transfer to other aspects of learning and life, allowing them to dare to face various challenges. In this way, students can gradually learn how to recover from setbacks, how to self-regulate when their emotions are low, enhance their emotional regulation ability, and face various situations in life with a more positive mindset34.

Interest is an important source of motivation for primary school students to participate in sports activities35. When primary school students become interested in a certain sports activity, they will participate in it more actively and enjoy the fun and sense of achievement brought by the sport. Interest can increase students’ participation and commitment and make them more focused on the sports activities themselves36. And interest can promote the learning and improvement of primary school students’ skills, so that they can make continuous progress in sports37. Some studies have shown that when PE teachers give students full autonomy and choice, students are able to choose more freely the physical activities they are interested in, thus increasing participation and physical activity levels38. Encouragement and support from PE teachers can stimulate students’ interest in sports. When students feel the attention and recognition of their teachers, they will participate more actively in physical activities and enjoy the fun and sense of achievement brought by sports. This positive emotional experience further promotes students’ love to physical activity39.

Physical activity level refers to the extent and frequency with which primary school students participate in physical activities in their daily lives40. Some studies have shown that an appropriate amount of physical activity has a significant positive impact on the physical and mental health of primary school students41,42,43. In terms of physical health, physical activity helps enhance primary school students’ cardiorespiratory fitness, muscle strength and bone density, and reduces the risk of obesity and chronic diseases44,45,46. In addition, it improves primary school students’ physical fitness and athletic ability, laying a solid foundation for their future physical activities and daily life. In terms of mental health, physical activity can relieve primary school students’ learning pressure, improve their emotional state, and increase their self-confidence and self-esteem47. Through participation in physical activities, primary school students can learn how to face challenges and difficulties and develop the mental quality of perseverance. At the same time, physical activity can also promote social interaction and teamwork among primary school students and enhance their social adaptability48.

Interest and physical activity levels may mediate the association between PE teacher autonomy support and the physical and mental health of primary school pupils. As we hypothesised above, interest and physical activity levels may play a mediating role in PE teacher autonomy support for primary school pupils’ physical and mental health. However, when both interest and physical activity levels were considered as mediating roles, it was important to explore whether there was a relationship between the two. Correlational studies have found significant correlations between interest and physical activity levels, with interest positively predicting physical activity levels36. PE teacher autonomy support positively affects physical and mental health by enhancing primary school pupils’ interest in learning PE, which in turn promotes their physical activity levels and ultimately their physical and mental health. This process formed a chain mediating role, with PE teacher autonomy support as the starting point, interest in PE learning as one of the mediating variables, physical activity level as one of the mediating variables, and physical and mental health as the end point.

The aim of this study is to investigate the impact of PE teacher autonomy support on the physical and mental health of primary school students and to analyse in depth the chain mediating role of physical activity level and interest in this process. As shown in Fig. 1, this study plans to construct a chain mediation model with the following hypotheses:

H1: PE teacher autonomy support has a significant positive predictive effect on the physical and mental health of primary school students.

H2: Interest plays an independent mediating role between PE teacher autonomy support and primary school students’ physical and mental health.

H3: Physical activity level acts as an independent mediator between PE teacher autonomy support and primary school students’ physical and mental health.

H4: Interest and physical activity level act as chain mediators between PE teacher autonomy support and primary school pupils’ physical and mental health.

Fig. 1
figure 1

Hypothetical chain intermediation model.

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Method

Participants and procedure

Based on the administrative divisions and varying levels of regional economic development across Jilin Province, China, one primary school was selected from each of the province’s three major geographical regions: eastern, central, and western. Using stratified sampling, two classes were randomly selected from each grade level in both urban and rural schools, totaling 36 classes. Participants were included based on the following criteria: (1) currently enrolled students in grades four through six; (2) obtaining informed consent from the student, parents, and school; (3) ability to understand and complete the questionnaire independently or with appropriate parental explanation. Exclusion criteria included: (1) questionnaires with missing content, answers exhibiting obvious patterns or random response behavior, (2) presence of severe physical illness or psychological disorders, (3) significant differences from the general student population that could lead to sample bias. All valid questionnaires included in the analysis ensured information completeness and response quality. A total of 613 questionnaires were distributed, the questionnaire data were selected and collated, invalid questionnaires were excluded, and finally 528 valid questionnaires were obtained, with a validity rate of 86.1%. Among them, 262 (49.6%) were boys and 266 (50.4%) were girls. There were 192 (36.4%) fourth graders, 150 (28.4%) fifth graders and 186 (35.2%) sixth graders. The age range of the subjects was 11.28 ± 1.02 years.

Our research team provided participants with a detailed explanation of the study’s objectives, significance, and questionnaire guidelines prior to its commencement. A group testing approach was employed, emphasizing the principles of anonymous completion, data confidentiality, and voluntary participation. In accordance with the Declaration of Helsinki, the research design underwent ethical review by the Human Research Ethics Committee of Northeast Normal University. Throughout this process, all invited participants participated voluntarily. Therefore, confidentiality was ensured, and written informed consent was obtained from the parents or guardians of all participants.

Measures

The following text describes the measures used in the current data collection for analysis. All scales (in Chinese) are included in the Supplementary Material.

PE teacher autonomy support scales

Adopting the Multi-Dimensional Perceived Autonomy Support Scale for PE developed by Tilga et al. from three different dimensions (Cognitive Autonomy Support, Procedural Autonomy Support, Organizational Autonomy Support) perceptions will deepen the understanding of the relationship between teacher autonomy support behaviours and PE adaptation outcomes49. The scale is scored on a 7-point Likert-type scale (1 = strongly disagree, 7 = strongly agree), with higher scores indicating higher PE teacher autonomy support. In this study, the Cronbach’s alpha coefficient for this scale was 0.77.

Physical and mental health scales

With the help of the KIDSCREEN questionnaire, the subjective health and psychological, spiritual and social well-being (HRQoL) of children and adolescents aged 8 to 18 years are recorded50,51. The KIDSCREEN-52 consists of 52 items in 10 HRQoL dimensions and is the most detailed version of the KIDSCREEN questionnaire. It includes Physical Health (5 items), Mental Health (6 items), Emotions and Moods (7 items), Self-Awareness (5 items), Autonomy (5 items), Relationships with Parents and Family (6 items), Financial Likelihood (3 items), Peer Relationships and Social Support (6 items), School Environment (6 items), and Social Acceptance (Bullying) (3 items). The scale was rated on a 5-point Likert-type scale. In this study, the Cronbach’s alpha coefficient for this scale was 0.81.

Interest scales

A total of 27 question types and 4 dimensions were involved in the PE Learning Interest Level Scale for Primary School Students developed by Wang et al.52,53. The 5 levels of Likert-type scale were used to rate the level of sports participation (9 questions), positive interest in PE learning (8 questions), negative interest in PE learning (7 questions), and the level of independent learning (5 questions) to measure the interest in PE learning, among which those belonging to the reverse scoring method were 6th, 8th, 13th, 16th, 20th, 22nd, and 25th, i.e., 1 scored 5 points, 2 scored 4 points, and 1 scored 4 points. 1 scored 5 points, 2 scored 4 points, 4 scored 2 points, 5 scored 1 point and the rest were positively scored. In this study, the Cronbach’s alpha coefficient for this scale was 0.76.

Physical activity level scales

The Chinese version of the Physical Activity Level Questionnaire for Children and Adolescents revised by Guo Qiang was used to investigate the physical activity level of primary school students53,54. The questionnaire is suitable for measuring children and adolescents aged 8 years and above. The questionnaire was designed as a 5-point Likert-type questionnaire with 9 questions in the main body. The Physical Activity Level Questionnaire for Children and Adolescents is a self-administered 7-day recall questionnaire designed to measure students’ overall moderate to vigorous physical activity levels, but cannot be used to measure physical activity energy expenditure or estimates of specific frequency, duration, and intensity information. In this study, the Cronbach’s alpha coefficient for this scale was 0.79.

Data analysis

Statistical analysis was performed using SPSS 26.0 software. Count data were expressed as case numbers and percentages (%). Comparisons among multiple groups were conducted using one-way analysis of variance (ANOVA). Correlation analysis between variables employed Pearson’s correlation coefficient. Additionally, a chained mediation model was constructed using Model 6 in the SPSS PROCESS macro program. In addition, mediation effect analysis was performed using the Bootstrap method (5,000 samples) with a bias-corrected nonparametric percentile approach, yielding 95% confidence intervals to test the validity of mediation effects. A confidence interval not containing zero indicated a significant parameter. P < 0.01 and P < 0.05 denoted statistically significant differences.

Results

Common method bias test

In this study, the questionnaire method was used and the survey process was based on students’ self-reporting; therefore, the issue of common method bias may arise during the measurement process. In order to minimise the effect of common method bias, this study used a balanced item order, anonymous questionnaire measurement procedure to control for common method bias during the administration process. In addition, a Harman one-way test was conducted on the collected data. The results showed that a total of 14 factors with a characteristic root greater than 1 were extracted and the variance explained by the first factor was 30.16%, which was less than the critical criterion of 40%, indicating that the common method bias had a small impact on this study.

Descriptive statistics and correlation analysis of the variables

The means, standard deviations, and correlations of the variables are shown in Table 1. The results of the correlation analyses indicate that PE teacher autonomy support is significantly and positively correlated with interest, physical activity level, and physical and mental health. There was a significant positive correlation between interest, physical activity level and physical and mental health, and a significant positive correlation between interest and physical activity level. The significant correlation of each research variable lays a certain foundation for the subsequent test of mediating effect.

Table 1 Performance and correlation analysis of PE teacher autonomy support, interest, physical activity level and physical and mental health.
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Relationship between interest and physical activity level: a chain mediation model

Before testing the model, the predictor variables involved in this study were tested for multicollinearity, and it was found that the variance inflation factors of all the predictor variables were not higher than 3, indicating that there was no serious multicollinearity problem. Therefore, this study controlled for the 2 variables of gender and grade level when analysing the data. The nonparametric percentile Bootstrap method was used to apply the model of the SPSS macro program PROCESS prepared by Hayes to estimate the 95% confidence intervals of the mediation effect by 5,000 samples sampling, controlling for gender and grade level; if the interval does not include 0, there is a mediation effect, and if the interval includes 0, there is no mediation effect.

Chained multiple mediating effects of interest and physical activity level in the prediction of PE teacher autonomy support on physical and mental health were analysed. As shown in Table 2, regression analyses revealed that PE teacher autonomy support significantly and positively predicted interest, physical activity level, and physical and mental health. Interest significantly and positively predicted physical activity level; interest and physical activity level significantly and positively predicted physical and mental health. Therefore, hypothesis H1 was verified.

As shown in Table 3, the mediation effect test results found that the total indirect effect value of interest and physical activity level was 0.467, with a confidence interval of [0.302,0.548] not including 0. The two mediating variables were able to mediate the effect between PE teacher autonomy support and physical and mental health. As shown in Fig. 2, PE teacher autonomy support could positively predict interest (β = 0.481, 95% CI = 0.043, 0.088, P < 0.01) and physical and mental health (β = 0.129, 95% CI = 0.153, 0.189, P < 0.01). Interest could positively predict physical activity levels (β = 0.478, 95% CI = 0.005, 0.042, P < 0.01) and physical and mental health (β = 0.539, 95% CI = 0.032, 0.082, P < 0.01). Physical activity levels can positively predict physical and mental health (β = 0.461, 95% CI = 0.012, 0.041, P < 0.01). The mediating effect of the model consisted of 3 paths. indirect effect 1: PE teacher autonomy support→interest→physical and mental health, with an effect value of 0.351, 95% CI [0.286, 0.405]. indirect effect 3: PE teacher autonomy support→interest→level of physical activity→physical and mental health, with an effect value of 0.127, 95% CI [0.139, 0.274]. Both paths had a Bootstrap 95% confidence interval. 95% confidence intervals do not contain 0, indicating that interest and physical activity level play a chain mediating effect between PE teacher autonomy support and physical and mental health. Therefore, hypotheses H2 and H4 were both tested.

The results of the study found that PE teacher autonomy support significantly and positively predicted the physical and mental health of primary school students, and that interest played a mediating role in the relationship between PE teacher autonomy support and the physical and mental health of primary school students; and that interest and level of physical activity played a chain mediating role in the relationship between PE teacher autonomy support and the physical and mental health of primary school students.

Table 2 Regression analysis of chain mediation model of interest and physical activity level.
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Fig. 2
figure 2

Chain mediation model of PE teacher autonomy support affecting physical and mental health (**P < 0.01). Indirect effect 1: PE teacher autonomy support→interest→physical and mental health. Indirect effect 2: PE teacher autonomy support→physical activity levels→physical and mental health. Indirect effect 3: PE teacher autonomy support→interest→physical activity level→physical and mental health.

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Table 3 Bootstrap analysis of mediated effect pathways.
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Discussion

This study conducted a cross-sectional survey on primary school pupils’ physical and mental health. By constructing a chained mediation model, it examined the relationship between PE teacher autonomy support and primary school pupils’ physical and mental health, as well as the role of Interest and physical activity level in this relationship. The findings provide valuable insights for promoting the cultivation and intervention practices aimed at enhancing primary school pupils’ physical and mental health.

The findings of this study indicate a significant positive correlation between PE teacher autonomy support and primary school pupils’ physical and mental health, consistent with previous research and validating H1. The study suggests that autonomy support provided by physical education teachers—such as offering choices and reducing control—enhances students’ intrinsic motivation and promotes their intention to engage in extracurricular exercise, thereby indirectly benefiting their physical and mental well-being. Although the subjects were junior high school students, the conclusions hold transferable value for the primary school stage55. PE teachers have the subject matter expertise to put themselves in the students’ shoes during the teaching process, which builds a good teacher-student relationship and enables students to be more motivated in situations related to PE learning as feedback to the high quality of teacher-student interactions56. One study investigated the impact of teacher autonomy support on the mental health of adolescents as a whole. Results indicated that initial state and changes in teacher autonomy support were positively associated with initial levels and trajectories of mental health57. In addition, a one-year longitudinal study found that perceived autonomy support from peers, parents, and PE teachers autonomy support plays an important role in improving physical activity and health among adolescents58. Therefore, PE teacher autonomy support plays an important role in promoting the holistic development of students.

This study found that Interest mediates the relationship between PE teacher autonomy support and primary school pupils’ physical and mental health, validating H2. Reinboth et al.‘s research found that autonomy-supportive behaviors from coaches/teachers can promote the psychological and physical health of adolescent athletes by meeting their psychological needs59. Similarly, a study found that PE teacher autonomy support can enhance students’ intrinsic motivation and positive emotions by fulfilling their basic psychological needs. PE teacher autonomy support significantly predicted students’ psychological need fulfillment and subjective well-being60. Physical education teachers’ autonomous support may first exert its influence through the psychological mechanism of stimulating students’ intrinsic interest, thereby fulfilling fundamental psychological needs. This subsequently translates into sustained physical activity behavior, indicating that interest plays a more central driving role within the mediating pathway. Satisfying these basic psychological needs not only promotes physical exercise but also fosters emotional experiences of enjoyment and pleasure during physical education learning by fulfilling these requirements. Gråstén et al. studied Finnish adolescents aged 11 to 13 and found that fulfilling the needs for a sense of competence and social belonging in physical education was a key factor significantly increasing participation in moderate to vigorous physical activity61. Yun et al.‘s research explored the positive correlation between the fulfillment of basic psychological needs and the intensity of activities in school physical education classes among Korean adolescents62.

This study found that physical activity levels did not exert an independent mediating effect, a result differing from that of Taylor et al. Their research demonstrated a significant mediating effect of physical activity between teacher support and health outcomes63. This discrepancy may stem from differences in the developmental stages of the study populations. This study focused on elementary school students, whose physical activity is more constrained by structured curriculum arrangements, whereas Taylor’s research targeted adolescents who exhibit greater autonomy. Nevertheless, our findings align with Ommundsen et al.‘s research, which similarly observed a significant weakening of the mediating effect of activity levels after controlling for psychological factors. This suggests psychological mechanisms may represent a more central pathway64. This complex pattern of partial conflict and partial consistency indicates that the mechanism underlying PE teacher autonomy support may be dual-moderated by developmental stage and cultural context. Future cross-cultural studies across different age groups are needed to clarify these boundary conditions.

This study further found that Interest and physical activity level exhibits a chain mediation effect in the relationship between PE teacher autonomy support and primary school pupils’ physical and mental health, thereby validating H4. PE teacher autonomy support stimulated primary school students’ interest in sport, which in turn led to an increase in their physical activity levels. In turn, increased physical activity levels further contributed to the physical and mental health of primary school pupils. This chain mediating role emphasises the importance of PE teacher autonomy support and the key role of interest and physical activity levels in promoting primary school pupils’ physical and mental health. Physically active lifestyles during primary school have health benefits, including improved cardiorespiratory fitness, muscular, skeletal and cardiometabolic health and a positive impact on body weight65. There is growing evidence that physical activity has a positive impact on cognitive development and socialization66,67. Current evidence suggests that many of the benefits continue into adulthood. Once primary school children develop a strong interest in physical activity, they become more physically active, leading to further increases in physical activity levels. Understanding the chain mediating role of interest and physical activity levels in the relationship between PE teacher autonomy support and the physical and mental health of primary school pupils is an important guide to educational practice. PE teacher autonomy support should focus on adopting teaching methods that encourage students to participate in physical activities according to their interests and abilities, and provide positive feedback and constructive guidance. At the same time, we should strengthen our focus on physical activity for primary school students and provide more opportunities and resources for physical activity in order to promote the healthy physical and mental development of primary school students. It should be noted that this study employs a cross-sectional data collection approach. While the chained mediation model reveals the associative pathways between variables, this design cannot fully establish causal relationships among them. The possibility of reverse causal pathways cannot be ruled out, and it is difficult to control for the influence of unmeasured potential confounding variables on the relationships between variables. In addition, China’s educational environment emphasizes collectivism, academic achievement, and respect for teachers, with physical education curricula typically characterized by high structure. This unique context may amplify the role of teacher-provided autonomy support. In an educational setting that relatively emphasizes conformity, the choices and autonomy opportunities offered by teachers may exert a more significant psychological impact on students than in Western individualistic cultures. Simultaneously, the study’s finding that interest mediation outperformed physical activity levels may relate to Chinese elementary students’ limited extracurricular time and reliance on school-based physical education programs. While these cultural institutional factors limit the direct transferability of findings to other educational systems, they underscore the necessity of examining self-determination theory mechanisms across diverse cultural contexts. Future research should conduct cross-cultural comparisons to explore how teacher autonomy support functions differently across varying educational philosophies and curricular structures. This will contribute to developing more culturally inclusive theoretical models.

Limitations and prospects

There are limitations to this study. A key methodological limitation of this study lies in its insufficient consideration of the data’s cluster structure. Since sampling employed whole-class cluster sampling, individual student data may exhibit intraclass correlation. Neglecting this data structure may lead to an underestimation of standard errors. This limitation suggests that current findings should be interpreted with caution. Future research should employ more appropriate methods, such as multilevel mediation models, to simultaneously estimate effects at both the individual and class levels. Additionally, this study was only a cross-sectional study that examined the correlations of the variables, and future research could use a longitudinal design to explore the causal relationships between the variables. All variables were measured using student self-report methods. This study employs self-report methods because PE teacher autonomy support, primary school pupils’ physical and mental health, interest and physical activity level are inherently subjective psychological perceptions, making self-report the most direct and effective way to capture such internal constructs. Furthermore, large-scale questionnaire surveys offer significant advantages in terms of operational feasibility and cost-effectiveness, making them well-suited for the scale of this research. While this approach effectively captures individuals’ subjective perceptions and experiences, it may be subject to social desirability bias, common method bias, or recall bias. For example, students may be unable to accurately recall their physical activity levels. Future research should use a multi-data source model to collect students’ physical activity levels and physical and mental health from the perspectives of PE teachers or parents, which in turn could be used to effectively reduce measurement bias and explore the validity of the model structure from multiple perspectives.

Conclusion

This study not only has certain theoretical significance, but also has a wide range of practical value (e.g., influencing pedagogical reform, promoting children’s health, supporting teacher development, etc.). Through data analysis, a model containing multiple mediating prediction paths was constructed, and the following research conclusions were obtained: (1) PE teacher autonomy support will effectively and positively predict physical and mental health; (2) PE teacher autonomy will significantly and positively predict physical health by promoting interest, and then (3) PE teacher autonomy support is associated with primary school children’s physical and mental health by influencing their interest, as well as by influencing their physical activity level. The role of these 3 pathways reveals the pathways through which PE teacher autonomy support indirectly helps elementary school students develop long-term exercise habits and enhance physical fitness and mental toughness through interest and physical activity, providing new ideas for preventing and intervening in childhood obesity and mental health problems.