Relationship Between Standing Long Jump Performance and Health-Related Indicators and Lifestyle Factors in Chilean Adolescents: A Cross-Sectional Study

Background: The standing long jump (SLJ) is a field-based test of lower-limb muscular fitness in youth and a proposed indicator of health-related physical fitness. However, evidence on its relationship with psychological, sleep, dietary, and lifestyle factors in adolescents remains limited, particularly in Latin America. Objective: To examine the association between SLJ performance and health-related indicators and lifestyle factors in Chilean adolescents. Methods: A cross-sectional study was conducted with 145 adolescents (16.02 ± 1.09 years; 99 males, 46 females) from a subsidized secondary school in Chile. SLJ performance, handgrip strength, body mass index (BMI), physical activity (PAQ-A), sleep quality (PSQI), dietary indices (HCI and UHCI), and psychological symptoms (DASS-21) were assessed. Associations were examined using Pearson’s correlation and multiple linear regression, with false discovery rate (FDR) correction for multiple comparisons. Results: SLJ performance was positively associated with handgrip strength (r = 0.59, p < 0.001) and physical activity (r = 0.42, p < 0.001), and negatively associated with BMI (r = −0.30, p = 0.001) and anxiety (r = −0.24, p = 0.011). Sleep quality showed a weak inverse association that was not significant after FDR correction. Dietary indices were not associated with SLJ performance. In the adjusted model, sex (β = 0.224, p = 0.013), BMI (β = −0.275, p < 0.001), handgrip strength (β = 0.435, p < 0.001), and physical activity (β = 0.229, p = 0.002) were independently associated with SLJ performance, explaining 57% of the variance (R2 = 0.57, adjusted R2 = 0.523). Conclusions: SLJ performance is mainly associated with muscular strength, physical activity, and BMI in Chilean adolescents, while psychological, dietary, and sleep variables are not independently associated after adjustment. These findings support SLJ as a practical indicator of muscular fitness, but not of overall health. Due to the cross-sectional design, causal inference is not possible.