This cross-sectional experimental study investigated the impact of varying approach-run distances (15 m, 20 m, 25 m, 30 m, and 35 m) on long jump performance among 146 novice early adolescents (aged 11–14 years; 75 boys, 71 girls) with no prior formal training in long jump or athletics. Participants from schools in Nadia district, West Bengal, India, performed randomized long jump trials from each distance following a standardized warm-up. Jump distances were measured from the take-off board to the nearest landing mark in the sand pit. Results showed no statistically significant differences in performance across the five approach distances for any age group or sex (p > 0.05), with mean jump distances remaining largely stable. Boys consistently outperformed girls, reflecting typical sex differences in strength and power, but both groups exhibited similar patterns of minimal variation. Small, non-significant improvements were observed at 20 m for boys, suggesting this distance may offer an optimal balance of acceleration and control. The findings indicate that beginner early adolescents achieve sufficient approach velocity with shorter run-ups (15–20 m) and do not benefit from longer distances due to limitations in technique, neuromuscular control, stride regulation, and maintenance of speed. These results support the use of shorter approach runs in youth training and physical education to prioritize rhythm, take-off mechanics, and consistency over maximal run-up length, particularly in resource-limited settings.