Education is a crucial topic in today’s world since nations’ development depends on it, particularly in unequal world regions like Latin America (Ferreira and Gignoux, 2011). Thus, a pivotal government task is to design and implement novel, cost-effective strategies for education improvement (Barnett, 2008). In this sense, academic achievement (ACA) is one of several educational indicators that emerge to bridge social, economic, and health gaps (Daude and Robano, 2015; Hahn and Truman, 2015). Unfortunately, the COVID-19 pandemic worsened ACA globally due to children’s depression, anxiety, decreased self-esteem, physical activity, and increased sedentary behaviors, which exacerbated educational inequalities (Runacres et al., 2021; Barbosa-Camacho et al., 2022). However, improving physical fitness seems to be a novel strategy for influencing ACA positively by enhancing physical and mental health and reducing cognitive gaps related to social vulnerability (Donnelly et al., 2016; Cristi-Montero et al., 2021).

Robust evidence points to a positive association between physical fitness (mainly cardiorespiratory fitness [CRF]) and ACA (especially in mathematics and English or Spanish as a first language) (Álvarez-Bueno et al., 2020). Besides, evidence also indicates that improving physical fitness can enhance executive functions, especially working memory, inhibitory control, and fluid reasoning (Donnelly et al., 2016; St Laurent et al., 2021). Executive functions refer to a family of top-down mental processes and there is general agreement that there are three core functions; working memory, which enables us to retain information, inhibitory control, which helps suppress automatic responses to stimuli, and cognitive flexibility, which allows us to shift attention between different aspects of a task or problem (Diamond, 2013). From these, high-order executive functions are built such as fluid reasoning and, is the ability to reason, problem solve, and to see patterns or relations among items (Diamond, 2013). All these cognitive abilities play a crucial role in overall cognitive performance and ACA (Ardila, 2008; Diamond, 2013; Blair, 2017).

Hence, adequate cognitive performance (CP) at school age is crucial due to the fact that it is a strong predictor not only ACA but also of health status and economic success in adulthood (Ursache and Noble, 2016). For instance, children with better physical fitness show greater macrostructure in some brain regions, improved microstructure, and increased brain functionality than peers with low physical fitness levels, which have been associated with better CP and ACA (Cadenas-Sanchez et al., 2020). However, all these improvements noted above have been related to neural activity patterns between different executive tasks, which are more sensitive during adolescence (Moisala et al., 2018; Williams et al., 2022). In this sense, there is a scarcity of literature exploring how each cognitive domain could contribute to (i.e., mediating) the relationship between physical fitness and different academic subjects (Visier-Alfonso et al., 2022). Moreover, based on the same principle, each academic subject could be affected by a specific or combination of cognitive domains; hence, expanding this research area beyond mathematics and language could improve our understanding of physical fitness contribution to ACA.

Through a parallel mediation approach, it is possible to establish the mediating role of several mediators, independently and jointly, in the relationship between a predictor and outcome (Kane and Ashbaugh, 2017). This sort of analysis differs from serial mediation because the last assume that one mediator leads the other mediator. In contrast, when mediators are in parallel, we cannot infer causality (Hayes and Andrew, 2013). Indeed, although mediators can be slightly correlated in a parallel approach, they must not create multicollinearity because it may affect the estimation of their partial relationships with the outcome variable (Hayes and Andrew, 2013). In this sense, this study addresses the gap in understanding the specific cognitive domains through which physical fitness impacts academic achievement.

Therefore, the study aimed to establish the parallel mediation role of four cognitive domains (i.e., working memory, fluid intelligence, inhibitory control, and cognitive flexibility) determined by a principal component analysis on the relationship between a global physical fitness score (GFS) and diverse subjects score and average academic achievement in adolescents.

This cross-sectional study is part of the Cogni-Action Project conducted between March 2017 and October 2019 (Solis-Urra et al., 2019). This project was retrospectively registered (8/July/2020) with the Research Registry (ID: researchregistry5791) and was approved by the Bioethics and Biosafety Committee of the Ethics Committee of the Pontificia Universidad Católica de Valparaíso (BIOEPUCV-H103-2016). This study was conducted according to the guidelines of the Declaration of Helsinki. Written consent was obtained from the school principal, parents/guardians, and participants before participation.

A gender-balanced sample of adolescents (50% male and 50% female) aged 10–14 participated in this study. Overall, there were diverse significant differences in variables between boys and girls; however, no interaction by sex was detected. No difference was observed between the imputed and non-imputed datasets. Table 1 shows a complete description of adolescents’ characteristics.

To examine the associations among global fitness scores, cognitive domains, and specific school subjects (Language, Mathematics, History, English, and Science), a correlation matrix was generated. The results of the correlation matrix are presented in Table 2. It is important to note that the correlations between cognitive components are zero, as they are derived from a principal component analysis where each generated component is independent of the others.

The results presented in Figure 2 provide a comprehensive overview of the mediations examined in this study. For a detailed description of the findings, including estimates (B non-standardized), 95% confidence intervals (CI), and p-values for the total, indirect, and direct effects, please refer to the Supplementary Figures.

Overall, when considering each academic score, our results revealed a full mediation for Language and English, while Mathematics, Science, and History exhibited partial mediation. Additionally, partial mediations were observed for both average scores, namely Academic-PISA and Academic average.

Specifically, for Language and English, the total mediation effects accounted for 92.5% (indirect effect, B = 0.015; CI [0.008, 0.021]) and 53.9% (indirect effect, B = 0.016; CI [0.009, 0.024]), respectively. Both academic scores demonstrated significant indirect effects on working memory, inhibitory control, and fluid reasoning.

Regarding Mathematics, Science, and History, the partial mediation effects were 43.0% (indirect effect, B = 0.019; CI [0.011, 0.018]), 43.8% (indirect effect, B = 0.016; CI [0.010, 0.023]), and 45.9% (indirect effect, B = 0.014; CI [0.008, 0.020]), respectively. In the case of mathematics, both working memory and fluid reasoning mediated the association with the global fitness score. However, for Science and History, working memory, inhibitory control, and fluid reasoning demonstrated significant indirect effects.

Furthermore, both Academic Average and Academic-PISA exhibited partial mediations (50.6%, B = 0.015; CI [0.008, 0.021], and 51.5%, B = 0.017; CI [0.010, 0.024], respectively), with significant indirect effects observed for working memory, inhibitory control, and fluid reasoning. No mediation effect was found for cognitive flexibility in any of the analyses.

Summary of all mediations addressing in this study. The arrows between cognitive domains indicate that they contribute to the total indirect effect. PCA: Principal component analysis factors and its cognitive tasks. The model was adjusted for age, PHV, WHtR, breakfast consumption, school type, and SVI.

The present study aimed to establish the parallel mediation role of four cognitive domains (i.e., working memory, fluid reasoning, inhibitory control, and cognitive flexibility) in the relationship between a global fitness score and various subject scores and average academic performance in adolescents. In this regard, our results show partial to full mediation of various cognitive domains in this relationship.

On the one hand for the association of GFS and ACA, several studies have shown a possible association especially of cardiorespiratory fitness on academic performance in language, mathematics, and science (Mullender-Wijnsma et al., 2016; McLoughlin et al., 2020; Pate et al., 2020). This evidence is consistent with our results in mathematics (43.0%), science (43.8%), history (45.9%), academic average (50.6%), and academic-PISA (51.5%), where we found a partial mediation of the cognitive domains in the GFS-ACA relationship so that improving fitness could positively influence these subjects through an improvement in cognitive performance. To the best of our knowledge, results in history are a novelty of this study.

The present results can be explained because executive functions and logical-mathematical thinking are related to the frontal and prefrontal lobes of the brain (Henri-Bhargava et al., 2018; Cristofori et al., 2019). CFR causes increased blood flow and oxygenation in this brain area and improves neuroelectric function, neuronal synopsis density (Hillman et al., 2008), neurotrophins related to neurogenesis, and angiogenesis in the brain (Best, 2010). In fact, the literature indicates that children with better CFR have greater total grey and white matter volume (Cadenas-Sanchez et al., 2020). MF also shows these improvements concerning brain function; this is produced by neuromuscular factors but seems to depend on the type of muscle contraction (Yao et al., 2016; Hernández-Jaña et al., 2021). However, regarding the volume of grey and white matter in the brain, the improvements from MF do not appear to be independent of CFR (Esteban-Cornejo et al., 2017, 2020).

On the other hand, we found complete mediation in Language (Spanish as a first language) and English (as a second language), indicating that while GFS is linked to ACA, its influence is largely mediated by improvements in cognitive abilities rather than a direct effect of physical fitness alone. These results are supported by several studies that obtained similar findings associating fitness with mathematics improvements but not reading skills (Hansen et al., 2014; Mullender-Wijnsma et al., 2016). It is worth mentioning that the cognitive domains that were significant in our mediation model for Language and English (working memory, inhibitory control, and fluid reasoning) were the same as for mathematics, history, science, Academic-PISA, and Academic Average.

The underlying mechanism that may explain the variations in performance between reading and mathematics tasks may be attributed to physiological differences in the brain. While these tasks may activate similar neural networks in terms of brain areas involved, the connectivity and myelination give rise to distinct functions within the neural network (Grotheer et al., 2019). In this sense, at the brain level, the areas related to language are Broca’s and Wernicke’s areas (Ono et al., 2022). Language brain areas first start with the language reception/understanding system (Wernicke’s area) and, second, the language production system (Broca’s area), which extends through the basal ganglia and thalamus (Ardila et al., 2016). In this sense, the evidence indicates that language skills are associated with better cognitive performance (Becker et al., 2016; Tremblay and Dick, 2016). In fact, bi-multilingual skills are associated with multiple cognitive benefits (Bialystok et al., 2006a,b; Poulin-Dubois et al., 2013), especially mental flexibility and inhibitory control (Garbin et al., 2010; Prior and Macwhinney, 2010). This may be due to language switching that develops inhibitory control processes (Bialystok and Barac, 2012). Likewise, these multilingual abilities may cause changes in areas of the brain, especially in the gray matter (Stein et al., 2012; Klein et al., 2014). Future studies should explore these differences at the brain level and in executive functions.

Based on our research findings, it is crucial to recognize that improving academic performance requires focusing on both physical and cognitive aspects. Enhancing overall physical fitness alone is not sufficient; rather, attention must also be given to cognitive performance, particularly executive functions such as working memory, inhibitory control, and fluid reasoning. To effectively implement these findings, it is necessary to establish national policies and guidelines that prioritize integrating physical activity into academic subjects and dedicating specific time for physical activity classes. This includes active breaks, school recess, and active commuting, as well as incorporating physical activities that stimulate cognitive functions directly into classroom lessons. Additionally, providing professional development opportunities for teachers is essential to equip them with the necessary tools for implementation. This comprehensive approach will enable students to achieve academic outcomes while promoting well-being.

In conclusion, this study highlights the intricate relationship between adolescents’ physical fitness and academic achievement, mediated by performance in diverse cognitive domains. The findings suggest that the association is not solely attributed to fitness improvements but is instead influenced by the convergence of cognitive functioning and physical fitness. Specifically, the complete mediation effect observed in Language and English subjects underscores the significant role of cognitive performance in shaping the relationship. Consequently, implementing targeted strategies that prioritize enhancing physical fitness among adolescents can impact academic achievements positively, contingent upon concurrent improvements at the cognitive level. These insights accentuate the importance of considering physical and cognitive aspects in interventions to promote adolescent academic outcomes.

In conclusion, this study highlights the intricate relationship between adolescents’ physical fitness and academic achievement, mediated by performance in diverse cognitive domains. Our findings indicate that physical fitness, is significantly associated with academic achievement through its influence on cognitive functions such as working memory, inhibitory control, and fluid reasoning. Specifically, the complete mediation effect observed in Language and English subjects underscores the significant role of cognitive performance in shaping the relationship. These results suggest that improvements in academic achievement are not solely due to enhanced physical fitness but also rely heavily on cognitive enhancements. Consequently, our study provides evidence that implementing targeted strategies to enhance physical fitness among adolescents may positively impact academic achievements, provided there are concurrent improvements in cognitive performance. These insights accentuate the importance of integrating both physical and cognitive aspects in interventions to promote adolescent academic outcomes.

The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.

The studies involving humans were approved by Ethics Committee of Pontificia Universidad Católica de Valparaíso (BIOEPUCV-H103–2016). The studies were conducted in accordance with the local legislation and institutional requirements. Written informed consent for participation in this study was provided by the participants’ legal guardians/next of kin.

CC-M: Conceptualization, Data curation, Formal analysis, Funding acquisition, Investigation, Methodology, Project administration, Supervision, Writing – original draft, Writing – review & editing. RM-F: Investigation, Writing – original draft, Writing – review & editing. JE-P: Writing – original draft, Writing – review & editing. AD: Writing – review & editing. JZ-C: Writing – review & editing. NA-F: Writing – review & editing. TR-A: Writing – review & editing. VS-C: Writing – review & editing. RI: Writing – review & editing. KS: Writing – review & editing.