Syed Danish Hamdani

Objective: This study aimed to develop age- and sex-specific normative percentile curves and percentile-based performance zones for core muscular endurance using the plank exercise test among adolescents aged 12–16 years in South Punjab, Pakistan, employing the LMS method and a back substitution procedure to assess internal consistency. Method: This cross-sectional study included 2, 970 adolescents (49.73% boys, 50.27% girls; mean age 14.00 ± 1.41 years) recruited from 60 higher secondary schools across South Punjab, Pakistan, using stratified random sampling in 2020, representing a pre-pandemic baseline. Height, weight, and BMI were recorded, and core muscular endurance was assessed using the isometric plank test. Age- and sex-specific normative references and smoothed percentile curves were established using the LMS (Lambda, Mu, Sigma) method. Internal consistency of the derived reference values was assessed using a back substitution procedure, in which the LMS model’s P50 (50th percentile) estimate for the full sample was compared against its P50 estimate for a randomly drawn 20% subsample of the same cohort, with the Mean Absolute Percentage Error (MAPE) used to quantify agreement. Sex differences were examined using the Mann-Whitney U test, with statistical significance set at p < 0.05. Results: Using the LMS method, the study established age- and sex-specific normative references and smoothed percentile curves for the plank test. Boys were significantly taller, heavier, and had higher BMI than girls (p < 0.001). Boys showed higher mean plank times (80.72 ± 73.48 s vs. 69.07 ± 58.16 s; p < 0.01), effect sizes ranged from negligible to small across all variables (rank-biserial r = 0.00–0.26), with r = 0.06 for plank performance. Median plank performance increased with age in both sexes, from 50 to 61 seconds in boys and from 44 to 66 seconds in girls between ages 12 and 16, with a steeper rise in the upper percentiles among boys. Age- and sex-specific percentile curves and performance cut-points across five zones; Very Poor, Poor, Medium, Good, and Excellent were derived. The majority of participants were classified as “Medium” (32.7%) or “Good” (24.4%), with 9.9% reaching “Excellent”. Boys’ “Excellent” threshold ranged from ≥133 seconds at age 12 to ≥227 seconds at age 16, while in girls it ranged from ≥127 to ≥126 seconds, peaking at ≥146 seconds at age 14. The back substitution procedure produced an average MAPE of 6.69% for boys and 6.04% for girls, supporting the internal consistency of the derived references within this population. Conclusion: This study provides the first age- and sex-specific normative references and percentile-based performance zones for the plank exercise test in Pakistani adolescents, with internal consistency supported by a back substitution procedure. These references offer simple, low-resource, population-based benchmarks for monitoring core muscular endurance, with practical value for physical education teachers, coaches, and health professionals working in school-based health initiatives. However, external validation using an independent sample, and replication in other regions of Pakistan, are needed before these references are applied beyond South Punjab.

Background: Childhood obesity and physical inactivity are growing global public health concerns. Once predominantly observed in wealthier nations, these issues are now increasingly prevalent in low- and middle-income countries. We aimed to examine the relationship between moderate-to-vigorous physical activity (MVPA) and physical literacy (PL) among children aged 8–12 years, and to determine whether body mass index (BMI) mediates this association. Methods: We conducted a cross-sectional study of 1,360 children (8–12 years old, mean age 10.0 ± 1.4 years) from 85 higher secondary schools in South Punjab, Pakistan. Physical activity and PL were assessed using the Canadian Assessment of Physical Literacy (CAPL-2) protocol. Data analyses included descriptive statistics, independent t -tests, chi-square tests, Pearson correlations, and multivariate logistic regression. A regression-based mediation analysis was conducted to examine the mediating role of BMI in the MVPA–PL relationship. Age and sex were included as covariates. Statistical significance was set at p < 0.05 (two-tailed). Results: Overall, 79.9% of participants were of normal weight, 9.7% were overweight, and 5.3% were obese. Normal-weight children demonstrated significantly higher average weekly step counts, more MVPA days per week (5.04 ± 1.09 vs. 4.65 ± 1.17), and higher PL scores (53.76 ± 11.72 vs. 45.86 ± 9.87) than overweight or obese children ( p < 0.001 for all comparisons). BMI was negatively associated with PA and PL measures ( r = −0.136 to −0.300, p < 0.01), while MVPA and step count were positively associated with PL ( r = 0.237 to 0.609, p < 0.01). In the mediation analysis, higher MVPA was associated with lower BMI (Path a: β = −0.377, SE = 0.078, p < 0.001), and lower BMI was associated with higher PL (Path b: β = −0.514, SE = 0.065, p < 0.001). MVPA also showed a strong direct association with PL ( c' = 2.091, SE = 0.189, p < 0.001). The indirect effect of MVPA on PL through BMI was statistically significant [β = 0.194, 95% CI (0.107, 0.291)], accounting for approximately 8.5% of the total effect. Sex-stratified analyses indicated that the proportion of the MVPA–PL association mediated through BMI was slightly higher in girls (10.2%) than in boys (7.1%). Conclusion: This study provides the first evidence from a Pakistani pediatric population that BMI partially mediates the association between MVPA and physical literacy, though the majority of this relationship remained direct. Children with overweight and obesity demonstrated lower PA participation and reduced PL scores than normal-weight peers, while girls consistently underperformed boys despite comparable BMI and knowledge levels. These findings support the need for culturally relevant, gender-responsive, school-based programmes that promote physical activity while addressing weight-related barriers in under-resourced settings.

Objective: This study examined whether psychological resilience mediates the association between anxiety and PA among Pakistani university students and, as a secondary aim, explored heterogeneity in these relationships using person-centred approach. Methods: A cross-sectional survey was conducted among 770 university students (aged 18–26 years) from six cities in Punjab, Pakistan, between May and December 2025. Participants completed validated measures of anxiety (GAD-7), psychological resilience (CD-RISC-10), and self-reported PA. Correlation, regression, mediation, and latent profile analyses were performed, controlling for gender and academic year. Results: Anxiety was significantly and negatively correlated with both resilience (r = −0.475, p < 0.001) and PA (r = −0.378, p < 0.001), while resilience was positively associated with PA (r = 0.419, p < 0.001). Physical activity was significantly predicted by anxiety (B = −0.383, p < 0.001) and resilience (B = 0.174, p < 0.001) in regression models, explaining 21.7% of the variance in PA. The mediation analysis revealed that resilience explained 39% of the total effect of anxiety on PA, indicating partial mediation. LPA revealed three distinct profiles: an Anxious–Inactive group (27.1%) characterised by high anxiety and low resilience; a Moderately Distressed–Moderately Active group (47.0%) with intermediate levels; and a Resilient–Active group (25.8%) with low anxiety and high resilience. Conclusions: Lower physical activity among Pakistani university students is partly explained by reduced psychological resilience in the context of anxiety. These findings highlight the importance of resilience as a protective resource and support integrated mental health and physical activity interventions in resource-limited university settings.