This Commentary provides evidence-informed policy guidance for strengthening Physical Education (PE) as a subject in South Africa by addressing long-standing inequalities in curriculum status, teacher preparation and professional development, and implementation at school level. Drawing on South Africa's Curriculum and Assessment Policy Statements (CAPS), UNESCO standards for quality PE, WHO frameworks, and practice-based evidence from the KaziBantu initiative, we demonstrate how coordinated partnerships and South African Council for Educators (SACE)-accredited in-service teacher training can operationalise quality PE in under-resourced schools. The Commentary offers insights for policymakers, education authorities and expert committees to support curriculum reforms and strengthen opportunities for continuing professional development for teachers, and advocates for sustainable, health-promoting school systems.

Background:Children with overweight or obesity are at elevated risk for later-life mental health challenges, but the role of accelerometer-derived waking movement behaviors remains uncertain. Thus, we examined longitudinal associations of sedentary behavior (SB), light-intensity physical activity (LPA), and moderate-to-vigorous-intensity physical activity (MVPA) at age 7 with later-life internalizing and externalizing problems. Method:We used data from the UK Millennium Cohort Study, focusing on children with overweight or obesity at age 7 who had valid accelerometer data and a complete set of predefined analytic variables (N = 858). Exposures were average daily minutes of SB, LPA, and MVPA. Outcomes were parent-reported Strengths and Difficulties Questionnaire-based internalizing and externalizing problems scores at ages 11 and 14. A generalized random forests approach was used to estimate average treatment effects (ATEs) and conditional average treatment effects (CATEs), adjusted for relevant demographic, socioeconomic, body mass index, parental distress, baseline mental health, and co-occurring movement intensities; day-of-week activity-pattern variables were used as exploratory candidate moderators. Results:Estimated ATEs were small. After applying the Benjamini-Hochberg false-discovery-rate (FDR) correction across the 12 primary exposure-outcome tests, only the association between higher SB and lower internalizing problems at age 11 remained statistically significant (ATE = -0.013 SDQ points per additional min/day; 95% CI, -0.019 to -0.007; q < 0.001). No other pathway survived FDR correction, and other nominal or directionally suggestive estimates were interpreted as exploratory. CATE summaries and calibration tests provided limited evidence of reproducible heterogeneity. Conclusions:Accelerometer-derived waking movement behaviors at age 7 were associated with later SDQ problems scores in small and outcome-specific ways among children with overweight or obesity. Since the study is based on observational data and relies on measured-confounder assumptions, the findings should be interpreted cautiously, and as model-based estimates rather than definitive causal evidence.

Background: Micronutrient deficiencies and physical inactivity can adversely affect child growth and development. This study assessed the effects of school-based physical activity and multi-micronutrient supplementation on micronutrient status among schoolchildren in Kilombero district, Tanzania. Methods: In a cluster-randomized trial, children aged 6-12 years were allocated to physical activity, multi-micronutrient supplementation, combined physical activity plus supplementation, or placebo control. Anthropometric and biochemical assessments were conducted at baseline, 14 months, and 26 months. Dried blood spot samples were available for 923 children at baseline. Complete-case analyses used biomarker-specific subsamples with valid baseline and 26-month measurements. Results: The primary complete-case sample included 243 children with valid paired measurements for zinc and serum transferrin receptor; vitamin D analyses were restricted to 52 children because of missing or invalid samples. At baseline, iron and vitamin D deficiencies were common, affecting 42.8% and 39.9% of children, respectively, while zinc deficiency affected 11.9%. At 26 months, allocation to the physical activity intervention was associated with lower odds of zinc deficiency, both when delivered alone (OR = 0.16) and when combined with supplementation (OR = 0.57). Supplementation alone was not significantly associated with reduced zinc deficiency. Iron status did not differ between intervention groups. Vitamin D findings should be interpreted with caution because analyses were based on a very small biomarker-specific subsample. Conclusions: School-based physical activity, alone or combined with multi-micronutrient supplementation, was associated with lower odds of zinc deficiency among Tanzanian schoolchildren. Supplementation alone showed no clear benefit for zinc or iron status. Vitamin D findings remain inconclusive because of substantial biomarker-specific missingness. Future trials should strengthen adherence monitoring, biomarker follow-up, and repeated assessment of dietary and contextual factors.

Background: Quantifying the dynamic interplay of waking movement behaviors, particularly physical activity (PA) and sedentary behavior (SB), through specific metrics such as the Physical Activity-Sedentary Time Balance index (PASTBI), has recently received increasing research attention in adults. However, there is a paucity of longitudinal studies applying this metric to elucidate potential associations with mental health in children. Thus, applying this approach offers a promising potential to improve our understanding of the long-term implications of movement behaviour balance on children's mental health trajectories, with important implications for intervention design. Methods: PA and SB of 5123 children were measured at age 7 using accelerometers, while mental health problems at age 11 were assessed using the Strengths and Difficulties Questionnaire. Specifically, PASTBI, defined as daily PA minutes divided by daily SB minutes, was categorized into 4 sex-based quartiles (Q1-Q4). Linear regression models were used to examine sex-stratified associations of PASTBI-related quartiles at age 7 years with internalizing and externalizing problems at 11 years. Results: Among boys, those in quartiles 3 and 4 of PASTBI at age 7-reflecting higher PA and lower SB-showed significantly lower internalizing scores at age 11 compared with boys in quartile 1 (eg., Q4: B =-0.841, 95% CI:-1.154 to-0.528). A higher PASTBI (Q4 versus Q1) was associated with higher externalizing problem scores at age 11 in both boys (B = 0.705, 95% CI: 0.409 to 1.002) and girls (B = 0.702, 95% CI: 0.421 to 0.983). Conclusion: Higher PA and lower SB levels are associated with fewer internalizing problems in boys, but with more externalizing problems across both boys and girls, suggesting a complex association between the balance of SB and PA with mental health in children. Future research, which investigates the role of developmental and contextual moderators, is required before more solid conclusions on the optimal balance of waking movement behaviors for mental health can be drawn.

Major depressive disorder (MDD) is highly prevalent and associated with substantial disease burden and significantly reduced life expectancy. Physical activity (PA) has been shown to reduce depressive symptoms to a similar extent as antidepressant medication. Despite this evidence, individuals with MDD engage in lower levels of PA and exhibit higher levels of sedentary behavior. Structural, physical, and psychological barriers hinder PA engagement. PA coaching offers a promising strategy to overcome these barriers and promote sustainable behavior change. Previous research highlights the importance of addressing affective responses to PA in interventions. Moreover, the support of technology-based tools, such as wearables, seems promising. This study aims to investigate the short- and long-term effects of a new PA coaching approach on PA behavior, depression severity, and quality of life in outpatients with MDD. Potential mechanisms of behavior change and participant experiences are also examined. This study uses a three-arm randomized controlled trial (RCT) design and is conducted at a psychiatric day clinic in German-speaking Switzerland. A total of 114 individuals aged 18 to 65 years with a clinical diagnosis of MDD (ICD-10: F32 and F33) are recruited on an ongoing basis and randomly assigned to one of three groups: (1) A 10-week PA coaching program based on interest and experience in PA, supported by a wearable smart ring for self-monitoring; (2) the same 10-week program extended by an additional, remote 26-week cognition-based coaching phase; or (3) a control group receiving treatment as usual along with written current PA guidelines. Data is collected at three measurement timepoints: 2-4 weeks after the start of day clinic treatment (baseline), after the 10-week coaching phase (post), and after a 6-month follow-up period (follow-up). The primary outcome is the change in device-measured PA over time (baseline, post, and follow-up), measured via Fibion® accelerometer, and analyzed using linear mixed models. A new PA coaching program is introduced to counteract low PA levels observed in individuals with MDD. By combining affective with cognitive components of behavior change, the intervention aims to promote a sustainable increase in PA and ultimately improve mental and physical health and quality of life. DRKS: DRKS00036209. Registered on 08 May 2025

BACKGROUND:On-task behaviour in the classroom, which partly relies on inhibitory control, contributes to academic achievement. Physical activity has much potential to facilitate on-task behaviour due to its positive association with inhibitory control. However, it remains unclear how the association between physical activity and on-task behaviour is influenced by its type and intensity as well as the sex of participants. AIM:To investigate sex-specific associations of type and intensity of physical activity engagement and on-task behaviour as well as its mediation by inhibitory control. SAMPLE:Cross-sectional study including 142 participants (47.2% boys) with a mean age of 11.6 years recruited from local schools. METHODS:Classroom behaviour was video-recorded, with a 6-min segment coded for on-task behaviour. Using a 7-day recall protocol, participants reported type and intensity of physical activity. Additionally, inhibitory control was assessed using a computerized Flanker task. RESULTS:While path analyses revealed no associations between physical activity intensity, inhibitory control and on-task behaviour, there was a sex-specific association with the type of physical activity. More frequent on-task behaviour was associated with greater participation in open-skill sports in boys (β = .27, p < .05) and more engagement in closed-skill sports in girls (β = .25, p = .05). However, this association was not mediated by inhibitory control. CONCLUSIONS:The type rather than intensity of physical activity seems to be associated with favourable classroom behaviour. Sex-specific relations between open- and closed-skill sports and on-task behaviour highlight the need for interventions tailored specifically to girls and boys.

Purpose Developing reliable instruments to assess physical activity (PA) and sedentary behaviour (SB) is crucial and challenging. PA questionnaires are user-friendly, but lack the accuracy of devices like accelerometers. The Simple Physical Activity Questionnaire (SIMPAQ) estimates structured PA, sedentary and in-bed time, and incidental PA through a structured interview. Due to its practicality, it may be used for various populations, including those at higher risk for SB. This study aimed to validate the Italian version of the SIMPAQ (SIMPAQ-It) among university students, a high-risk of SB population, comparing results with accelerometer data and the International Physical Activity Questionnaire Short Form (IPAQ-SF). Methods Anthropometric and sociodemographic data were collected in 106 participants (57 females) with age range from 19 to 36 (M age = 21.8; SD = 2.3). Afterwards, participants wore accelerometers (Actigraph-GT3X) for one week, before the SIMPAQ and the IPAQ-SF were telephone-administered. Results The SIMPAQ-It demonstrated moderate correlations with accelerometer data, particularly for sleep duration (rho = 0.49, p < .001) and sedentary time (rho = 0.22, p < .05). Additional correlations included standing time with light PA (rho = 0.25, p < .01), walking time with daily steps (rho = 0.24, p < .05), and sport/exercise time with moderate-to-vigorous PA (rho = 0.36, p < .001). In comparison, the IPAQ-SF showed lower correlations with accelerometer data, with the strongest association observed for vigorous PA (rho = 0.33, p < .01). Although the IPAQ-SF took less time to complete (p < .001), participants found it easier to respond to the SIMPAQ (p = .004). Conclusions This study highlights that the Italian version of the SIMPAQ could be a valid tool for assessing SB and PA in university students, showing stronger correlations with accelerometer data compared to the IPAQ-SF, especially for lower-intensity activities. Despite some limitations, the SIMPAQ-It is practical and user-friendly, making it suitable for applications in research, educational and clinical settings.

Children in low- and middle-income countries are disproportionately affected by socioeconomic disparities, which might influence access to diverse and nutritious foods, increasing the risk of food insecurity and low dietary quality. Hence, monitoring of these conditions is crucial. This study examined whether children from households with different wealth status vary concerning food insecurity, dietary diversity, consumption of specific food groups, and risk of stunting. Baseline data were utilized from a multi-country randomized intervention trial. Primary school children (Mage= 8.3±1.4 years; 416 girls and 423 boys) from four schools in a marginalized, peri-urban area (government-defined wealth index quintile 3) in Gqeberha, South Africa, participated. Parents/guardians provided information about household socioeconomic factors and completed a 24-hour food item checklist and a food security questionnaire. Stunted children were defined as <-2 SD height-for-age compared to current World Health Organization child growth standards. Analyses of variance and χ2-tests were employed to compare children classified into five wealth quintiles. On average, children consumed food items from 5.8±2.0 healthy food groups. One out of 12 children (8.4

While adolescence is a key period to shape healthy lifestyles, overweight/obesity and mental health problems are both prevalent among adolescents worldwide, yet evidence on physical activity and mental health remains limited for adolescents with overweight/obesity, particularly regarding gender and day type (weekday vs. weekend). We analyzed 1,238 adolescents with overweight/obesity from the UK Millennium Cohort Study (45.3% boys; M age = 14.25 years, SD = 0.34). At age 14, accelerometer-measured MVPA was assessed separately for one weekday and one weekend. At age 17, internalizing and externalizing problems were assessed using SDQ subscales. Associations were examined using survey-weighted negative binomial regression, with SDQ scores modeled as count outcomes. Models adjusted for sociodemographic, family, cognitive, and baseline mental health factors, and analyses were stratified by gender and day type. On weekdays, higher MVPA was associated with fewer internalizing problems among girls (IRR = 0.988, 95% CI [0.978, 0.997]), but not boys, corresponding to about 1.2% lower symptom rate per 10 min additional MVPA per day. On weekends, higher MVPA was associated with fewer internalizing problems in the overall sample (IRR = 0.992, 95% CI [0.984, 1.000]), corresponding to about 0.8% lower symptom rate per 10 min additional MVPA per day. No significant associations were found for externalizing problems. Higher MVPA was associated with modestly lower internalizing problems among adolescents with overweight/obesity, although effect sizes were small and patterns varied by gender and day type. Contextual factors may be important in understanding these associations.

INTRODUCTION:Accurately measuring aerobic endurance in military and police Special Operations Forces (SOF) and in load-bearing sports requires a cardiopulmonary exercise test protocol that incorporates load and terrain demands. We developed a ramped treadmill test incorporating a 12.6 kg vest and incremental incline and evaluated its validity against a standard speed-ramped protocol. MATERIALS AND METHODS:Twenty-three healthy and trained volunteers completed both protocols in randomized order. Breath-by-breath V˙O2 and heart rate data at the ventilatory thresholds 1 and 2, as well as V˙O2max were compared using Bland-Altman plots, two one-sided tests (TOST), as well as Bayesian range of practical equivalence (ROPE) using ±2.84 ml/kg/min (V˙O2) and ±3.1% (HR) pre-defined boundaries for insignificant difference. RESULTS:Mean test duration was 710 ± 85 sec with both protocols. V˙O2max differed by -0.2 ml/kg/min (95% CI -1.3 to 0.9). TOST did not confirm strict equivalence, but Bayesian ROPE placed 100% of the posterior within ± 2.84 ml/kg/min. Submaximal V˙O2@VT2 and HR thresholds met 95% ROPE criteria; V˙O2@VT1 narrowly missed. CONCLUSIONS:A vest-loaded, incline-ramped CPET designed for SOF tasks and sports disciplines that involve carrying additional load produces practically equivalent values of V˙O2max compared to a traditional speed-ramped protocol. The new protocol allows for accurate V˙O2 and heart rate measures for SOF and athletes carrying weight on steep terrain, while also providing a task-specific experience.

Physical activity (PA) has positive effects on physical and mental health. Nevertheless, two thirds of individuals with major depressive disorders (MDD) do not meet PA recommendations. Furthermore, MDD is associated with increased cardiovascular risk and autonomic nervous system dysfunction. This depression-related dysfunction is expressed by low heart rate variability (HRV). In contrast, regular PA has been shown to improve autonomic regulation over time as indicated by higher HRV values. The overarching aim of this umbrella review is to examine the complex interrelationship and mutual influence between MDD, PA, and HRV. We aim to answer the following questions: (I) How does PA affect depressive symptoms? (II) How are HRV and MDD related? (III) How does PA affect HRV? Medline, Embase, PsycINFO, SPORTDiscus, and Epistemonikos were searched for systematic reviews and meta-analyses from their inception until 5 July 2024. Reviews were included if they presented the effects of PA interventions on depression severity in individuals with MDD for part I, if they showed the differences in HRV parameters between healthy individuals and individuals with MDD for part II, and if they presented the effects of PA interventions on HRV parameters in healthy individuals for part III. The quality of the included reviews was assessed by Assessing the Methodological Quality of Systematic Reviews (AMSTAR 2) criteria. This umbrella review included 90 reviews. Part I shows that various types of PA are effective in reducing symptoms of depression in individuals with MDD. In addition, there is a similar reduction with PA compared with pharmacological treatment. Part II demonstrates that time-based and frequency-based HRV values are lower in individuals with MDD than in healthy individuals. Part III shows that different types of PA can improve time-based, frequency-based and nonlinear HRV parameters in healthy individuals. This comprehensive umbrella review demonstrates the importance of PA to reduce symptoms of depression and to have a positive impact on autonomic function. Further studies suggest that PA can also improve HRV in individuals with MDD. In the future, randomized controlled trials should be conducted to examine which types and forms of PA are effective in positively affecting HRV in individuals with MDD according to standardized parameters in the area of HRV and depression severity. The protocol for this umbrella review was a priori registered with PROSPERO: CRD42021278665.

In 2017, the International Judo Federation (IJF) changed weigh-in rules, shifting the weigh-in to the day before competition and introducing random weigh-ins on competition day. However, the impact of these new rules remains unclear. This study compared the effects of these weigh-in procedures on body mass, nutritional intake, psychological aspects, and performance. Twenty-six judo athletes (night before weigh-in: n = 13; same day weigh-in: n = 13) were assessed for body mass, nutritional intake, psychological factors, and performance under two weigh-in conditions: the night before and in the same day of competition. No significant differences (P > 0.05) were found in the prevalence (77% vs. 75%) or magnitude (4.37% vs. 3.49 %) of rapid weight loss between the night before weigh-in group and the same day weigh-in group, respectively. However, the night weigh-in group presented a higher post-weigh-in energy intake (night weigh-in: 44.8 +/- 11.1 kcal.kg(-1).day(-1) vs. same day weigh-in: 15.6 +/- 10.4 kcal.kg(-1). day(-1)) and carbohydrate intake (night weigh-in: 5.62 +/- 1.38 g.kg(-1). day(-1) vs. same day weigh-in: 2.06 +/- 1.40 g.kg(-1). day(-1)) (p < 0.001). Additionally, the night weigh-in group exhibited higher response times in cognitive tasks at day +1 compared to day 10, in relation to the same day weigh-in group (p = 0.025; 95% CI diff = 1.79, 26.07), while technical performance did not differ between groups. These findings highlight the need for better nutrition management and awareness of the psychological risks associated with rapid weight loss practices in judo.

Introduction: As one of the core executive functions, working memory involves the temporary storage and mental manipulation of information. These processes are essential for effective performance across a wide range of tasks (Miyake & Friedman, 2012). Military settings are often characterized by high physical and psychological demands. How individuals process information under such stressful conditions is therefore critical for successful performance. Consequently, it is important to identify the factors that contribute to an efficiently functioning working memory. Previous research has demonstrated associations between physical fitness and executive functions (e.g., Huang et al., 2015). However, few studies have examined this relationship in young, healthy adults, particularly within military contexts. The aim of the present study was therefore to investigate associations between working memory and physical fitness in a young, healthy population in a military setting. Methods: One hundred thirty-four male recruits from the Infantry School of the Swiss Armed Forces, with a mean age of 19 years, participated in the study. Working memory was assessed using a spatial N-back task administered with E-Prime. Reaction time and accuracy were extracted as outcome variables, separately for target and non-target trials. Physical performance was measured using the Swiss Army’s official fitness test, which included a shuttle-run test to assess aerobic endurance, as well as two muscle-strength tests: holding a plank position for as long as possible and pushing a medicine ball as far as possible with both hands from a seated position. Results: Correlation analyses revealed a significant positive association between the Shuttle run performance and accuracy in the spatial N-back task (r = .27, p = .003). In contrast, no significant correlations were found between the two strength tests and working memory performance (r = -.03, p = .73; r = -.004, p = .97). Discussion/Conclusion: Higher working memory performance is associated with better aerobic fitness amond young adults in a military setting. This result is consistent with previous findings with other populations (e.g. Noh et al., 2024) and may have practical implications for training in such environments. However, more research is needed to elucidate a causal relationship and potential benefits of interventions in a military setting. References Huang, T., Tarp, J., Domazet, S. L., Thorsen, A. K., Froberg, K., Andersen, L. B., & Bugge, A. (2015). Associations of Adiposity and Aerobic Fitness with Executive Function and Math Performance in Danish Adolescents. The Journal of Pediatrics, 167(4), 810–815. https://doi.org/10.1016/j.jpeds.2015.07.009 Miyake, A., & Friedman, N. P. (2012). The Nature and Organization of Individual Differences in Executive Functions: Four General Conclusions. Current Directions in Psychological Science, 21(1), 8–14. https://doi.org/10.1177/0963721411429458 Noh, K., Baumgartner, N. W., Onbasi, S. I., & Kao, S.-C. (2024). The relationship of aerobic fitness with verbal and spatial working memory: An ERP study. In Progress in Brain Research (p. S0079612324000578). Elsevier. https://doi.org/10.1016/bs.pbr.2024.04.003

PurposeThe six-minute walk test (6MWT) is one of the most widely utilized submaximal tests to assess cardiorespiratory fitness in both healthy and clinical populations. The present study aims to provide 6MWT reference values for Italian adolescents (11-18 years) and to identify key variables influencing the six-minute walk distance (6MWD).MethodsData were collected from 3276 Italian adolescents (48% males). Participants provided self-reported age, height, weight, and weekly practice of moderate-to-vigorous physical activity (MVPA). 6MWT was performed to assess participants' cardiorespiratory fitness.ResultsAverage distances of 730.0 (IQR: 674.0-788.0) and 675.0 (IQR: 624.0-720.0) meters were walked in the 6MWT by male and female adolescents, respectively. Multiple linear regression models, used to investigate whether demographics, anthropometrics, and MVPA predicted the 6MWD, revealed statistically significant results in both males (p < .001, F = 28.94, adjusted R2 = 0.11) and females (p < .001, F = 23.00, adjusted R2 = 0.09). In male adolescents, MVPA and age positively predicted the 6MWD, whereas BMI negatively predicted the 6MWD. In female adolescents, MVPA positively predicted 6MWD, whereas age and BMI negatively predicted 6MWD. No interaction effects were found.ConclusionThe reference percentiles of distance walked, classified by sex and age, reported in the present study can be used as a practical tool to assess adolescents' cardiorespiratory fitness. This study also highlights the importance of PA engagement in this population, as it was considerably associated with the average distance walked. Consequently, in addition to anthropometric and demographic variables, future studies should pay particular attention to the amount of MVPA practiced.

Introduction Students enrolling in higher education often adopt lifestyles linked to worse mental health, potentially contributing to the peak age onset of mental health problems in early adulthood. However, extensive research is limited by focusing on single lifestyle behaviours, including single time points, within limited cultural contexts, and focusing on a limited set of mental health symptoms.Methods and analysis The UNIversity students’ LIFEstyle behaviours and Mental health cohort (UNILIFE-M) is a prospective worldwide cohort study aiming to investigate the associations between students’ lifestyle behaviours and mental health symptoms during their college years. The UNILIFE-M will gather self-reported data through an online survey on mental health symptoms (ie, depression, anxiety, mania, sleep problems, substance abuse, inattention/hyperactivity and obsessive/compulsive thoughts/behaviours) and lifestyle behaviours (ie, diet, physical activity, substance use, stress management, social support, restorative sleep, environment and sedentary behaviour) over 3.5 years. Participants of 69 universities from 28 countries (300 per site) will be assessed at university admission in the 2023 and/or the 2024 academic year and followed up for 1, 2 and 3.5 years.Ethics and dissemination The study was first approved at a national level in Brazil (CAE:63025822.8.1001.5346). Study sites outside Brazil obtained additional ethics approval from their institutions using the main approval. Results from the UNILIFE-M cohort will be disseminated through scientific publications, presentations at scientific meetings, press releases, the general media and social media.

Introduction: High dropout rates during the selection of Special Operations Forces (SOF) are well-documented and often linked to inadequate physical preparedness and subsequent injuries. Training recommendations in a preparatory selection phase may offer a strategy to reduce dropout. Objective: To assess whether fitness-related dropout was reduced in a study population of SOF candidates receiving training recommendations after fitness assessment, compared to historical attrition rates. Methods: Using a prospective observational design, male candidates across Swiss Armed Forces and police SOF units received individualized training recommendations in the preparation phase of the main selection period. Dropout due to inadequate physical preparedness for the demands of SOF selection and basic training was tracked through all selection stages. A Bayesian analysis compared observed fitness-related dropout rates with a historical control group using a Meta-Analytic Predictive approach. Results: Fitness-related dropout occurred in 29% of participants (40 of 137), compared to ahistorical average of 42%, corresponding to a relative reduction of over 30%. The posterior probability of a reduced dropout rate (odds ratio <1) was 91.6%. Conclusion: Targeted training guidance as part of human performance management may help to reduce fitness-related dropout rates among SOF candidates.

ABSTRACT School is widely recognized as one of the primary sources of stress among adolescents. While some studies employing laboratory‐based stressors have suggested that adolescents with better cardiorespiratory fitness (CRF) may exhibit lower stress reactivity to psychosocial stressors, research based on real‐life stressors is lacking. Therefore, we examined whether CRF predicts physiological and psychological reactivity in response to a real‐life stressor (mathematics exam). Students were recruited from Swiss public schools (9th grade). The final sample included 67 students (58% female, Mage = 15.09 years). Heart rate (HR), heart rate variability (HRV), mood states, and state anxiety were used as indicators stress reactivity. CRF was assessed using the 20m shuttle‐run test. Statistical analyses used regression analyses, which were controlled for relevant social and demographic confounders, as well as baseline outcomes during a nonstress condition (normal mathematics lesson). Exposure to the mathematics exam resulted in decreased HRV and mood, alongside increased state anxiety. While better CRF was associated with lower HR, higher HRV, better mood, and lower state anxiety across stress and baseline conditions, CRF did not predict physiological and psychological outcomes after controlling for baseline scores and confounders. Hence, our study suggests that although better CRF is associated with favorable physiological and psychological states, this relationship appears independent of students' current stress exposure. Further research employing other ecologically valid stressors is needed to better understand the impact of CRF on real‐life stress reactivity. From a school health perspective, it is essential to support students in developing the capacity to cope effectively with academic stressors.