Introduction

Since the 1970s, learning motivation has gradually become one of the focal points of second/foreign language learning research. The social-educational model (SEM) proposed by scholar Robert Gardner, which combines instrumental motivation and cognitive motivation, has become one of the most important theories in traditional motivation research1. However, with the development of globalization, English has gradually become a universal language, and the motivation for language learning is no longer limited to instrumental and integrative motivation2. The social education model has been questioned by many scholars because the single perspective of previous studies cannot explain the complexity of second language learning motivation3. To compensate for the shortcomings of Gardner’s theory, Dörnyei proposed a new theoretical framework based on the inheritance and development of traditional motivational theories: the L2 Motivational Self System (L2MSS)4. Since then, L2MSS has become the most dominant theoretical framework in the field of second language acquisition motivation research. Lee employed L2MSS in the context of the Korean language family, evaluated the L2 willingness to communicate (L2 WTC) of college and high school students, and constructed a language learning prediction model for the East Asian Peninsula5. Moreover, Welesilassie employed L2MSS to examine the chain-mediated relationship between English language learning and language proficiency among Ethiopian matriculated high school students6. Nowadays, in the context of further development of globalization, research based on L2MSS theory is not only limited to English, but has begun to intersect with other languages and even cultural behaviors, and has further expanded the scope of research in language psychology.

With China’s growing international influence and the deepening process of globalization and regionalization, especially the “Belt and Road” initiative, which has received great attention and recognition from the international community, China has become one of the preferred destinations for foreign students. According to the China Student Aid Development Report 2017, the number of international students coming to China has increased to 443,000 since 2016, and most of them come from countries along the Belt and Road. Due to its unique location, Beijing is the capital of China and has the largest number of major universities and the largest number of international students in China7. By 2023, the total number of foreign students in Beijing will exceed 40,000, the highest number of international students in China8. In the process of international students coming to China to study, Chinese language as one of the compulsory courses takes up more than one-sixth of the time in all courses for international students. Despite the huge proportion of Chinese courses, learners generally need to spend a lot of time and energy, but the result may not be satisfactory, because its glyphs, rhythms and compositions are more complicated than those of English9. Therefore, how to effectively improve the effectiveness of Chinese language learning has become one of the hot topics in Chinese language science and language psychology.

The WHO’s Mental Health Gap Action Programme (mhGAP) 2023 suggests that physical activity (PA), a non-pharmacological intervention, can be effective in improving an individual’s cognitive and executive functioning and academic performance10. At the same time, there is also evidence that PA is effective in improving individuals’ efficacy and learning mood in second language learning11. However, as the level of PA increases, some studies have found that there are differences in the improvement effects of different levels of PA on second language learning. For example, Tarkington found that adolescents with regular PA habits had less negative affect and academic difficulties than a blank control group. This effect also gradually increased with the amount of exercise12. Similarly, Du found that there is a threshold for the positive contribution of PA to academic effectiveness by constructing a CHAID decision tree. Specifically, students with 16–25 min of PA at least once a week outperformed approximately 88% of other students in terms of GPA and foreign language learning13. So far, although the enhancement effect of PA on the effectiveness of second language learning has been confirmed, there is still insufficient evidence to prove whether it is applicable to Chinese language learning.

In summary, in order to explore the dosage characteristics of PA in enhancing the efficacy of Chinese-based second language learning, the present study, by constructing a chain-mediated model, for the first time incorporates and analyzes PA as a mediating variable in the process of influencing L2MSS on learning experience and intended effort. At the same time, we would like to elucidate the psychological mechanism and brain structure underlying this process, and provide a more scientific exercise prescription for international students and language enthusiasts to learn Chinese. In light of Dörnyei’s English-as-a-second-language-based learning motivation prediction model14, this study proposes a theoretical model applicable to Chinese language learning for non-Chinese speaking international students. The following hypotheses are put forth in this regard: (I) There was an ameliorating effect of PA on the presence of L2MSS, learning experience, and intended effort, and this effect may be positively correlated with intensity. (II) The PA as facilitator can make a positive contribution to the learning experience and the intended effort.

Materials and methods

Participants

Using the cluster random sampling method, 981 international students from different countries from 8 universities in China were initially selected as the subjects of the study, taking the international student classes in each university as the unit. The inclusion criteria for the subjects were: (1) The subjects were selected from a pool of exchange or international students enrolled at universities and colleges, including those pursuing undergraduate, master’s, and doctoral degrees. Prior to their inclusion in the study, the recruited subjects underwent screening for identity, nationality and native language. (2) Prior to the commencement of the experiment, the subjects were requested to provide a self-report on their mental health status. A Mini-Mental Status Examination (MMSE) was conducted to ensure that all subjects achieved a score of greater than 24 on the MMSE15. Additionally, the student affairs department at each institution responsible for international students was consulted to ascertain any psychiatric history and cognitive ability by means of a review of individual files. (3) Prior to the commencement of the trial, a questionnaire was employed to initially ascertain whether the subjects had indeed volunteered to participate in the trial and had not declined to engage in any of the testing activities proposed in this study. (4) Informed consent for the survey was given by the counselor (classroom teacher), and the questionnaire was completed after signing it. Finally, 856 scales with valid results were obtained after all the collection work, and the validity rate of the questionnaires was 87.25%. In order to ascertain which results are to be regarded as invalid, the following criteria must be taken into consideration: (1) The response time is insufficient or excessive (less than 30 s or greater than one hour). (2) In the event that the responses provided to the fill-in-the-blank questions are deemed to be implausible or arbitrary, it may be inferred that the respondent did not approach the questionnaire in a serious manner. Consequently, the questionnaire is deemed to be invalid. (3) A questionnaire with identical responses to all the options suggests that the respondent did not peruse the questionnaire with sufficient attention, and thus the questionnaire is deemed invalid. (4) Questionnaires that have been completed with incomplete answers or with empty fields that have not been filled in. (5) A considerable number of questionnaires were submitted from the same IP address, particularly from the same location within the educational establishment. The procedures were conducted in accordance with the National Institutes of Health Guidelines (This study adheres to the standards set forth by the Investigator-Initiated Clinical Trial Resources section of the NIH Guidelines for Human Experimentation. These guidelines establish protocols for experiments involving human participants, with a particular emphasis on the protection of both participants and researchers. The Guidelines are currently employed globally in the context of clinical trials and RCT) and were approved by the Ethics Committee of Human Experimentation of Beijing Normal University (Authorization No. TY20220905). This is to certify that all methods were carried out in accordance with the relevant guidelines and regulations. The requisite information consent forms were obtained from all subjects.

Procedures

In this study, the parameters of PA and the degree of effort expended in the pursuit of Chinese language learning were quantified using scales based on a range of indicators. During the testing process, all indicators were distributed via the SoJum software platform, which is owned by Tencent Holdings Ltd. Prior to data collection, the research team provided respondents with an explanation of the purpose and methodology of the survey, addressed any queries directly, and obtained consent from respondents to complete the scales with the assistance of their counsellors, class teachers, or class instructors. The process of completing the scale was anonymous and did not require the disclosure of personal information such as identity card or student number. In addition, invalid responses, responses completed in less than 200 s, and responses that were identical to ten consecutive options were eliminated. The questionnaire was also designed to ensure high levels of homogeneity.

Measurements

Level of physical activity

Physical activity was measured using the short version of International Physical Activity Questionnaire (IPAQ)16. IPAQ assigned metabolic equivalent (MET) corresponding to different intensities of PA by asking the study subjects about the frequency of the week (d/wk) and the time of day (min/d) for that intensity. The MET was 3.3 for walking, 4.0 for MPA, and 8.0 for VPA. The PA level for each intensity and the total PA level were calculated separately according to the formula.

Physical activity levels were categorized and grouped into 3 levels according to the criteria recommended by the IPAQ working group17: (1) High level PA group (HG). VPA time ≥ 3d per week and total MET ≥ 1500, or PA time ≥ 7d per week and total MET ≥ 3000; (2) Moderate level PA group (MG). Weekly VPA time ≥ 3d and daily PA time ≥ 20 min, or weekly MPA ≥ 5d and daily PA time ≥ 30 min, or weekly PA intervals ≥ 5d and total MET ≥ 600; (3) Low level PA group (LG), with PA levels insufficient for the above criteria. The Cronbach α is 0.772 in the study.

The IPAQ formula is defined as follows:

  1. ①

    Walking MET × min/wk = 3.3 × Walking weekly frequency(d/wk) × Walking daily time(min/d).

  2. ②

    MPA MET × min/wk = 4.0 × MPA weekly frequency(d/wk) × MPA daily time(min/d).

  3. ③

    VPA MET × min/wk = 8.0 × VPA weekly frequency(d/wk) × VPA daily time(min/d).

  4. ④

    MVPA MET × min/wk = ② + ③.

  5. ⑤

    Total PA MET × min/wk = ① + ② + ③.

Second language learning motivation

Second language learning motivation was measured using Dörnyei’s standardized L2 motivational self-system scale, which includes the ideal L2 self and the ought-to L2 self14. Most of the items in the scale were developed based on previous research conducted in China and Japan18. The rubric is measured on a six-point Likert scale or a six-point subscale. In this case, a score of 1 represents not at all and a score of 6 represents an extremely high degree. The questionnaire has been pilot tested with 100 high school students and has high reliability. Furthermore, Merih and Li validated the scale’s reliability through a large sample cross-sectional screening study6,19. The Cronbach alpha for the ideal L2 self is 0.742 and for the thought-to-L2 self is 0.796 in this study. Both have high consistency reliability coefficients.

Learning experience assessment

The experience of learning Chinese language is based on Papi’s Learning Experience Scale, which has been modified to capture the experience of learning Chinese language18. The scale consists of six items that assess the environmental experience, interest, time feeling, anticipation, desire to learn, and satisfaction of learning Chinese language, which are also measured by a six-point Likert scale or a six-point rating scale. Among them, a score of 1 represents not at all and a score of 6 represents an extremely high degree. Considering the linguistic and environmental variability of the respondents and the cited questionnaire, the cited questionnaire was compiled and modified according to the standardized back-translation method proposed by Brislin before the formal survey20, and was finally determined to be a bilingual version in Chinese and English. Kormos’s study initially validated the reliability of the scale for the first time based on English as a second language, yielding favorable test results21. Subsequently, Wang corroborated the continued high reliability of the scale in mixed Chinese-English contexts through cross-sectional experiments, and demonstrated that the Cronbach alpha exceeds 0.822. The scale has high reliability and validity, with a Cronbach alpha of 0.812 in this study.

Intended effort analysis

Intended effort was assessed using Papi’s Effort Scale. In this study, the scale is modified based on Chinese language learning14. The collected indicators include six items, namely: time spent, initiative, focus, compliance self-discipline, and purposefulness. The scale is measured on a six-point Likert scale or six-point subscale. Where a score of 1 means not at all and a score of 6 means to an extremely high degree. In previous studies, Taguchi has demonstrated the high reliability of this scale in Chinese, Japanese, and Middle Eastern contexts with a sample size of 1,011 participants, with Cronbach alpha exceeding 0.723. In this study, the Cronbach Alpha was 0.704, which meets the acceptable level of 0.6 as suggested by Hair24.

Initial hypothesized model

Referring to Csizér & Taguchi’s previous study25, this study included PA in the mediator model based on the chain mediator model with ideal L2 self, should L2 self, English learning experience, English anxiety, and intended effort as variables. variables for SEM construction and path analysis. The relationships between these variables are shown schematically as red or blue arrows. The nine hypothesized causal paths are indicated by single-headed arrows, with the only relevant path (between ought-to L2 self and ideal L2 self) being a bidirectional path. The three paths from ideal L2 self or ought-to L2 self to learning experience, intended effort, and English anxiety can be interpreted as follows: all three dependent variables are increased or decreased by the two independent variables. In this case, learning experience, as a mediating variable, may affect the linear relationship between the main independent variable and the dependent variable and play a moderating role. Meanwhile, this hypothesis will be verified by the effect size and effect value ratio. For the original model, see Fig. 1.

Fig. 1
figure 1

Original reference model based on L2 motivational self-system, Intended Effort, English Anxiety. (+) is a positive path, (-) is a negative path.

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Statistical analysis

In this study, we mainly used difference-in-differences, correlation analysis, and mediated chain modeling to analyze the different indicators. First, SPSS 21.0 was used to test the normality of physical activity, ideal L2 self, ought-to L2 self, learning experience, and intended effort one by one, and descriptive statistics were performed after determining the type of data. The initial stage of the process entails the screening and categorization of all data, with the objective of eliminating any invalid values and outliers. Subsequently, the data were subjected to repetition to ascertain their consistency and accuracy. Subsequently, following the completion of the standard tests, all data obtained in this study is suitable for parametric statistical analysis. Subsequently, further tests of variance may be conducted26. Since the main variables in this study were categorized as low, moderate, and high PA, the analysis of variance (ANOVA) was used for the test of variance and the P, F values with 95% CI were reported. The data were corrected for noncompliance with the hypotheses using the Greenhouse-Geisser method. Data that were not consistent with the hypotheses were corrected using the Greenhouse-Geisser method. To explore the correlation and effect size among variables, Pearson’s test was used to analyze the results, and r and P values were reported. After reviewing the correlation results, the valid variables were included in structural equation modeling (SEM) by AMOS 24.0 for mediated chain model analysis and fitting to explore the path characteristics among the variables. After standardizing each result, Model-6 in the SPSS process canonical macro program plug-in was used for chained mediation effect testing and confidence interval estimation. The significance of each path was then tested using the bootstrap method. Finally, the Bonferroni test was used for post hoc testing of all indicators, and the significance threshold was set at P < 0.05.

Results

Effect of physical activity on L2 motivational-self and intended effort of college students in learning second language

The results of the analysis demonstrated a statistically significant main effect of PA on L2MSS, learning experience, and intended effort. However, the results of the ANOVA indicated that there were statistically significant differences in the effects of varying levels of PA on the three groups. With regard to L2MSS, while the ideal L2 self was not statistically distinct between the three groups, the HG exhibited a markedly elevated ought-to L2 SELF in comparison to the MG with LG (F = 4.23, P = 0.408, η²=0.0523). Secondly, the learning experience of the three groups was found to be statistically indistinguishable from one another.

In the comparison of the ideal L2 self sub-indicator, Q1 and Q2 represent the individual’s identification with the second language, respectively. In this section, both MG and HG were observed to be higher than LG (F = 2.03, P = 0.436, η²=0.0569; F = 3.83, P = 0.401, η²=0.0497). Nevertheless, the two groups exhibited minimal differences. This indicates that an increase in exercise levels is associated with an enhancement in the individual’s second language identity. Q3 and 4 pertain to the sustainability of individuals engaged in second language learning. In this section, only Q4 demonstrated minor discrepancies. In particular, HG demonstrated a greater propensity to pursue university-level Chinese courses than MG and LG (F = 3.10, P = 0.416, η²=0.0488; F = 5.97, P = 0.353, η²=0.0432). This suggests that individuals who engage in high levels of physical activity over an extended period are more sustainable in Chinese language learning, and therefore more conducive to the development of language habits. Q5 and 6 pertain to the extent to which individuals anticipate proficiency in a second language. The results demonstrated that Q5 exhibited a significant difference between HG and MG (F = 4.64, P = 0.366, η²=0.0340), as well as between MG and LG (F = 2.26, P = 0.428, η²=0.0503). Additionally, a notable distinction was observed between HG and LG (F = 7.25, P = 0.311, η²=0.0389). This indicates that individuals with higher motor levels tend to have greater expectations of learning Chinese language.

In the comparison of the overall L2 self-sub-indicator, Q1 and Q2 represent the level of self-esteem based on second language learning. In this section, HG’s Q2 is observed to be higher than that of MG and LG (F = 2.78, P = 0.397, η²=0.0452; F = 4.22, P = 0.294, η²=0.0348). This indicates that only a higher level of physical activity can positively influence an individual’s self-esteem in the context of learning Chinese language. Q3 and 4 pertain to others-based self-esteem in the context of second language learning. In this section, no significant difference is observed in the expression levels of the three groups. This indicates that PA does not result in notable alterations in individuals’ perceptions of others. Q5 and Q6 pertain to second language-based self-control. In this section, only Q6 demonstrated higher HG and MG than LG (F = 2.94, P = 0.416, η²=0.0539; F = 3.94, P = 0.452, η²=0.0443). This suggests that only a high level of PA is associated with enhanced self-control in the context of learning Chinese language.

In terms of intended effort, PA level all triggered differences in all sub-indicators. Among them, endeavor degree showed a stepwise increasing trend with PA level (F = 7.21, P < 0.01, η²=0.0473). And in terms of time spent, initiative, focus, compliance, self-discipline, and purposefulness, HG were higher than the other two groups, although LG were not significantly different from MG (F = 5.93, P = 0.036, η²=0.0308; F = 3.16, P = 0.0425, η²=0.0447; F = 2.33, P = 0.348, η²=0.0552; F = 2.87, P = 0.0264, η²=0.0416; F = 1.98, P = 0.0313, η²=0.0409; F = 1.76, P = 0.0410, η²=0.0421). This result also implies that there is a significant effect of PA on L2MSS, learning experience, and intended effort, but increasing the PA level leads to more significant improvements in ought-to l2 self, endeavor degree, and time spent. Detailed results are presented in Table 1.

Table 1 Characterization and difference in various variable with different PA level.
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Correlation between physical activity and various psychological factors in learning second language

The correlation results showed that PA was correlated with most of the sub-indicators in L2MSS, learning experience, and intended effort by Pearson correlation test. Based on PA, there were strong correlations between PA and both Ideal L2 self and Ought-to L2 self in terms of L2MSS (r = 0.692, r = 0.757, P < 0.05). In terms of learning experience, PA showed a significant positive correlation with time feeling (r = 0.810, P < 0.01) and remained positively correlated with ambient experience, interest, anticipation, learning desire, and satisfaction remained positively correlated (r = 0.521, r = 0.796, r = 0.674, r = 0.591, r = 0.443, P < 0.05). In terms of Intended effort, there was a significant positive correlation between PA and Focus and Self-discipline (r = 0.824, r = 0.809, P < 0.01), and correlated with time spent, initiative, compliance, and purposefulness (r = 0.653, r = 0.687, r = 0.751, r = 0.574, P < 0.05).

In terms of L2MSS, a correlation existed between ideal L2 self and ought-to L2 self (r = 0.429, p < 0.05). Both were correlated with ambient experience, interest, anticipation, and satisfaction (r = 0.305–0.702), except for Time feeling, which was significantly positively correlated with time feeling (r = 0.814, P < 0.01). Also, both were correlated with all sub-indicators of intended effort (r = 0.337–0.729, P < 0.05). For learning experience, there was almost significant correlation between all sub-indicators (r = 0.792–0.907, P < 0.05). In addition, learning experience was positively correlated with all sub-indicators of intended effort, and in particular, there was a significant effect of satisfaction on time spent, initiative, focus, compliance, and purposefulness (r = 0.828, r = 0.934, r = 0.866, r = 0.821, r = 0.878, P<0.01). In terms of intended effort, there was a strong positive correlation between the sub-indicators except for time spent and initiative which corresponded to self-discipline and purposefulness (r = 0.833–0.917, P < 0.01). This result also indicates that more than 90% of the main variables and sub-indicators are significantly correlated with each other, which can be further tested for mediation effect27. Detailed information is shown in Table 2; Fig. 2.

Table 2 Correlation results between PA and different table variables.
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Fig. 2
figure 2

Correlation heatmap between physical activity and individual variables.

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Chain-mediated relationship and psychological pathway between L2 motivational self-system and intended effort

This study examined the mediating effect of PA between L2MSS, learning experience, and intended effort using SEM analyses with AMOS 24.0.SEM is a data estimation method for large samples, and the sample size should not be too large or too small. To ensure that the sample size is sufficient to make the results of the study accurate, the method proposed by MacCallum, Browne & Sugawara was used to calculate the sample validity in this study before conducting the model analysis28. Assuming a model check value of 0.8, H0 = 0.05 and H1 = 0.08 in the RMSEA assumptions with a predicted degree of freedom of 100, respectively, confirmed that the sample size included in this study met the basic requirements. To make the model more streamlined, each of the three levels of PA was itemized as the three observed variables of PA.

Results showed that ideal L2 self, ought-to L2 self, and PA all had direct effects on learning experience and intended effort. Of these, ideal L2 self had the largest effect size on intended effort (β = 0.88, t = 8.41, P < 0.01), followed by PA (β = 0.66, 0.51, t = 4.31, P < 0.01), and after that ought-to L2 self (β = 0.46, t = 2.93, P < 0.01) and learning experience was relatively least significant (β = 0.43, 0.38, t = 2.12, P < 0.01). It also shows that all three have a positive predictive effect on intended effort, with ideal L2 self having the most significant effect. For detailed information, see Table 3.

Table 3 Fitting degree of original hypothesized model.
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Fig. 3
figure 3

Chained intermediary model between L2 motivational self-system and intended effort.

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In this study, the mediating effect of each indirect pathway effect and the estimation of its confidence interval were examined by Bootstrap program test with repeated sampling 5000 times. The test results show that Bootstrap 95% confidence intervals for the four indirect pathways with PA and learning experience as mediating variables do not contain 0, which indicates that the mediating effects of all pathways reach a significant level, and the mediating effects of both are significant in the process of the L2MSS role intended effort. In this model, the mediating effect consists of the indirect effects generated by the 4 mediating paths, where the total standardized indirect effect value is 0.562, 95%CI=[0.163, 0.387], which accounts for 59.61% of the total effect. The results of the 4 mediating paths indirect effects are as follows: (1) The effect value of the “ILS→PA→IE” pathway was 0.265, 95%CI=[0.124, 0.527], accounting for 31.28% of the total effect value. (2) The effect value for the “OLS→PA→IE” pathway was 0.179, 95%CI=[0.074, 0.256], accounting for 17.94% of the total effect value. (3) The effect value for the pathway “ILS→PA→LE→IE” was 0.116, 95%CI=[0.042, 0.248], accounting for 10.69% of the total effect value. (4) The effect value of “OLS→PA→LE→IE” was 0.108, 95%CI=[0.039, 0.126], accounting for 4.15% of the total effect value. In addition, the total standardized direct effect size of L2MSS on intended effort was 0.562, 95%CI=[0.163, 0.387]. Taken together, the amount of direct and indirect effects of ideal L2 self on intended effort was greater than that of ought-to L2 self, and there was a positive incentive effect of PA and learning experience. The specific structural equation model and path parameters are shown in Fig. 3; Table 4.

Table 4 Bootstrap analysis of the mediating effect test.
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Discussion

As China’s influence in the international arena gradually increases, there is an observable concomitant expansion in the use of the Chinese language29. Concurrently, it attracts a significant number of international students from across the globe to pursue their studies in China30. For this group of people, Chinese is a compulsory subject in all programmers and requires international students to have a certain level of language proficiency31. Nevertheless, owing to the intricacy of the sounds, shapes and composition of the characters, Chinese is frequently regarded as a ‘devil’s language’32. Therefore, the present study sets out to analyze the effect of PA on Chinese as second language learning, from the perspective of intended effort based on L2MSS. Furthermore, the study seeks to provide the field of language psychology with a theoretical foundation and reference results from movement science.

The first finding of this study is that there is a significant enhancement effect of PA on L2MSS, learning experience, and intended effort, but the dose may vary depending on the PA level. The results of this study showed that international students with high levels of weekly PA habits had higher scores in ought-to L2 self, endeavor degree, and time spent. And students with medium PA level scored higher than those with low level in all other areas. This also indicates that hypothesis (I) can be accepted. This result is similar to some of the previous studies. Kormos & Siidetkoon found through a cross-sectional survey that the higher the proportion of daily trips with the number of trips abroad, the higher the level of ideal L2 self and ought-to L2 self when learning a second language21. They also scored highly in terms of intentional effort, as evidenced by the amount of time they spent on second language learning compared to those with low PA levels33. To examine whether PA can promote second language learning efficacy by improving ideal L2 self and ought-to L2 self, Yashima found through a long-term follow-up study of more than five years that in purposeful non-native language environments, an individual’s communicative style undergoes a process from physical behavior to verbal communication. In the process, activities such as PA, especially team sports such as soccer, basketball or baseball, are more likely to interact with the learner’s ideal and ought-to L2 self, and will intrinsically transform the second language self into a part of life gradually34. In terms of learning experience, Martin argues that most learners’ motivation stems mainly from successful learning experiences in the early stages of foreign language learning, which include collaborative discussions, competitions, or sports activities, and are related to the influence of contextual factors such as the teacher, classmates, and textbooks35. In this study, PA as a mediating variable is effective in moderating the learning experience and increasing intended effort, and this effect becomes more significant as the level of PA increases. In addition, there are studies that differ from the present findings. Through multifactorial linear regression analysis, Magid found that ideal L2 self and ought-to L2 self were not influenced by other mediating factors to improve second language learning outcomes; instead, family, regional, and individual attitudes toward Chinese language learning were crucial36. However, this study speculates that this may be due to the fact that Magid’s subjects were middle school students, a group that is not as detached from their families of origin and has more discretionary time than college students, and thus may have a more homogeneous approach to PA or other activities that does not fully utilize the moderating effect of PA on the learning experience. However, what is different from the past is that although a large number of studies have explored the dominant role of L2MSS in second language learning, the present study, based on this study, for the first time takes PA as a mediating variable to analyze its facilitating effect in L2MSS. And it is concluded that PA can effectively enhance the dominant role of ideal L2 self and ought-to L2 self in L2MSS and can improve the individual’s learning experience. and increasing the level of PA can make the effect more significant.

The second finding of this study was that PA was a significant positive predictor of L2MSS, learning experience, and intentional effort, and that PA as a mediator had a positive facilitating chain relationship with all three. In the present study, PA was significantly positively correlated with all three and constituted a significant moderator. In the SEM model, the effect sizes between ideal L2 self and ought-to L2 self exceeded 0.6, with parallel mediated relationships. And the effect sizes all increased with PA participation. This suggests that by assessing an individual’s PA level, learning experience and intended effort can be inferred, thus improving the efficacy outcomes of Chinese language learning. The result also shows that hypothesis (II) can be accepted. This is more consistent with the results of previous studies. Similar to the present study, Stephen also examined the effects of PA levels on second language acquisition and academic achievement of 526 non-native English speaking third graders by constructing a SEM. The results showed that individuals with higher PA levels or VPA habits had higher developmental reading proficiency, English language proficiency, and math academic achievement than those without exercise habits. However, the effect may differ by ethnicity and gender37. Also using children as a sample, Adrià’s study also assessed the effect of participants’ weekly amount of PA on academic performance and executive function, including foreign language, through cross-sectional screening It was found that there was no significant difference between the medium PA level and low PA level population on most of the indicators, but the high PA level students were higher than the former in GPA, trial making test, foreign language academic achievement, BMI and CRF, and PA constituted a direct and profile pathway of positive facilitation for all indicators in academic achievement, academic mood and executive functioning38. This effect is not only found in children; Akira examined the effects of PA on English learning, family structure, and motivation in 608 Japanese middle school students, using aerobic fitness (AF) as a mediator. It was found that there were direct effects of PA on all three indicators, and the mediating effect of AF was more than 30%39. This is also consistent with the results of the multiplicative benefits of PA in this study. Similarly, Liu also analyzed Chinese students’ English academic efficacy using L2MSS. It was found that PA positively predicted students’ competence in L2 word picture, vocabulary discrimination, sentence semantic judgment, and listening discrimination in L2 learning, while increasing participants’ levels of ideal L2 self and ought-to L2 self40. Although the facilitating effect of PA in enhancing L2MSS effectiveness has been widely demonstrated, few studies have included PA as a mediating variable in their analyses. Instead, this study was the first to use PA as the main dependent variable and two aspects of L2MSS as independent variables, with the goal of not imposing PA as an intervention on learners. Rather, we analyzed individuals’ motivation from the perspective of the ideal L2 self and the ought-to L2 self, and in the process, assessed whether the inclusion of PA could enhance individuals’ spontaneous effort and Chinese language learning experience through a proactive approach. Based on the above results, this study concluded that for learners in non-Chinese-speaking regions, the main factors dominating Chinese language learning are still ideal L2 self and ought-to L2 self, and learners’ motivation can be enhanced through PA to improve their Chinese language learning experience and effort.

The aforementioned phenomenon can be elucidated from the vantage point of psychological and physiological mechanisms. Dual-Mode of Self-Control Theory and Self-Determination Theory well illustrate the role of PA in the L2MSS-dominated moderation of the learning experience versus the intended effort under the dominance of L2MSS. Among them, the dual-mode theory of self-control suggests that self-control consists of two systems: impulse and control (also known as rationality and emotion), and that the impulse system is the body’s tendency to produce automatic emotional responses and behavioral associations to stimuli, essentially without individual cognitive involvement. The control system is a higher order process that inhibits impulsive responses and is responsible for emotional management and decision making41. In the process of language learning, the individual is removed from the native language environment and therefore needs a higher level of self-control to engage in the learning process. Those with high levels of PA are generally motivated to learn and practice spontaneously, and thus will show higher levels of desire for the L2 self in the L2MSS. Self-determination theory suggests that an individual’s basic motivation stems from a psychological need for autonomy, competence, and relatedness. From a language learner’s perspective, prolonged engagement in sports, especially in group programs, significantly increases an individual’s self-identity and short-term decision-making ability, thereby enhancing cognitive flexibility in executive functioning42. In the process of learning Chinese language, learners are subjected to various difficulties and stresses at the initial stage due to the complexity of tones, rhythms and strokes, etc. Good second language learners need a higher level of stress tolerance and self-regulation. At this point, individuals with PA habits in this area are sometimes revealed. Since they have a clear goal and great spontaneity every time they engage in PA. As a result, this mental path continues during the second language learning process and manifests itself in a higher sense of purpose and level of self-determination in long-term PAs than in non-habituated individuals. The mediating role of PA between L2MSS on learning experience and intentional effort can be explained by the theories of the famous psychologist Erich Fromm. He considered PA as “an anesthetic for the maintenance of my cognitive and social relationships”43. On the other hand, according to Shavelson’s multilevel-multidimensional structural model of self-esteem, physical self-esteem, as a subset of self-perception, also triggers adjustments in global self-esteem when there is a lesser degree of physical change44. Because long-term PA itself improves posture, it also has a positive feedback effect on overall self-awareness, including language learning and executive function45. For this reason, PA is often recognized by the WHO or AHA as the best means of improving mental health and enhancing academic performance. With regard to the neural mechanisms involved, it has been demonstrated that prolonged aerobic exercise promotes the generation and volume increase of neurons in the hippocampus, particularly in the dentate gyrus46, while also enhancing the functional connectivity of the prefrontal cortex (PFC) and corpus callosum. This ultimately leads to an improvement in grey matter density and information integration47. It also modulates middle cerebral blood flow velocity and glucose metabolism, improving working memory and cognitive flexibility48,49. Regular PA also modulates amygdala activity, reducing reactivity to negative stimuli50. It also improves striatal activity and modulates dopamine pathways that are critical for addiction and reward mechanisms51. In addition, PA inhibits the serotonin reuptake transporter (SERT) by activating the 5-HT-related pathway in the raphe nuclei52, which promotes learning engagement and language learning efficiency53. Finally, long-term PA also increases the secretion of inhibitory transmitters such as endocannabinoids, acetylcholine (Ach) and GABA54,55, modulates the LC-NE system and activates brain regions involved in language learning56.

In summary, under the dominance of L2MSS, PA can be used as a mediator to effectively enhance the individual’s aspired L2 self, both in terms of executive power and self-discipline in the process of Chinese language learning, and to enhance the learning experience in order to increase the intended effort and academic performance. Therefore, based on the results, this study suggests that language learners in non-Chinese-speaking regions can improve their learning efficiency by regularizing PA in the process of learning Chinese language. For schools, teachers can incorporate activities or competitions involving PA into the process of teaching Chinese. Details can be found in the Performed Culture Approach57 proposed by Galal Walker and Situational Language Teaching (SLT)58 by Harold Palmer & A.S. Hornby. Based on this, learners can be encouraged to maximize the level and intensity of PA within acceptable limits, in accordance with Principle of Appropriate Load and Principle Of Motivation In Sport59,60. This allows you to evaluate and adjust single or phased training programs based on ratings of perceived exertion (RPE), HRmax and MET61,62. In order to achieve the optimal level of PA load, the goal is to maximize the mediating role of physical activity in the L2MSS-guided Chinese language learning and second language learning process.

Limitations and suggestions for future research

In this study, we compared the differences in L2MSS, learning experience, and intended effort during Chinese language learning among international students with different levels of PA and explored the correlations and chain relationships among the different indicators. The goal is to improve the process of Chinese language learning and help international students and non-Chinese speaking learners increase the effectiveness of second language learning. Therefore, we included college students from eight colleges and universities within Beijing by means of a cross-sectional large-sample survey and analyzed the differences in the participants’ outcome indicators in different aspects of language learning mediated by low, medium, and high PA levels as the main variable. However, there are several limitations to this study.

First, although four indicators were included in this study to compare differences between populations, the experimental design was a cross-sectional survey, and no longitudinal follow-up was done. Looking at previous large-sample surveys, we can see that some of the studies were compared sequentially by screening the NHANES, SEER, and CHARLS databases and standardizing the metrics by Weighted Mean Difference (WMD). This has the advantage of increasing the sample size while allowing the parameters of the longitudinal intervention to be analyzed in the study. However, the originality of the original research is lost. Instead of searching previous databases, this study collected and compared data from a cross-sectional sample over a period of approximately 1 year. Therefore, the originality of the study should be emphasized, but at the same time, there are some limitations regarding the strength of the results.

Second, this study aims to provide college students with more accurate exercise prescriptions that may reduce problem behaviors. Therefore, some recommendations should be made regarding the dosage requirements of PA that include both “intensity” and “volume” factors. However, in this study, only the volume of PA was divided according to the IPAQ (MET), and the intensity of training was not discussed too much. Therefore, it cannot be considered a precision exercise prescription in the strict sense. This is due to the typological characteristics of this study. Since this study focuses on modeling multifactorial mental pathways with PA as the main variable, the continuous variable (MET) was categorically transformed. However, because PA intensity is difficult to monitor in large-sample studies such as HIIT and MICT, it can only be implemented in future intervention trials or longitudinal studies.

Although the above problems cannot be ignored, this study attempted to circumvent the heterogeneity of results caused by the experimental design through Bootstrap and Bonferroni within the limited experimental conditions. We will also include factors such as longitudinal outcomes, PA volume, and gender differences in our analyses and recalibrate the core of the study in future studies. Based on these results, we will continue to improve the reliability and rigor of the study. To provide an effective exercise prescription and theoretical reference for the internationalized development of Chinese language and the psychology of language.

Conclusion

(1) PA has an ameliorative effect on L2MSS, learning experience, and intentional effort, and increasing the level of PA increases the significance of this effect. Specifically, MPA for at least 3 days per week can improve the efficiency of Chinese language learning. (2) Positive predictions of L2MSS, learning experience, and intended effort can be made by assessing PA level. (3) PA is an important mediator in the process of L2MSS influencing learning experience and intended effort, so regular PA can increase the amount of effect of this pathway, which can improve the outcome, experience, and adherence of individuals in second language learning.