Implementation schedule and exercise components.

BackgroundChina’s national school health policies face persistent implementation gaps, particularly in rural high schools prioritizing Gaokao. National surveys (2010–2019) documented alarming fitness declines: 50-m sprint speeds decreased (+0.3s boys; + 0.4s girls), pull-ups/sit-ups fell 29%/20%, and standing jumps shortened 6–7 cm.MethodsA 16-week cluster quasi-experiment assigned intact rural high school classes (N = 98; age = 16.35 ± 0.48years) to: • Experimental (n = 50): Feature Recess-Time Sports Activities (FRTSA; 5x30-min/week). • Control (n = 48): Standard supervised running. Blinded assessors conducted the National Student Physical Health Standard tests.ResultsFRTSA elicited significant improvements versus control: • Speed: 50-m sprint (p η2 = 0.18, d = 0.75). • Explosive Power: Standing jump (p = 0.022, η2 = 0.05, d = 0.41). • Flexibility: Sit-and-reach (p 2 = 0.12, d = 0.60). • Strength: Male pull-ups (p = 0.030, d = 0.41); female sit-ups (p = 0.029, d = 0.45). No endurance benefits emerged (1000m/800m: all p > 0.05, d ≤ 0.18).ConclusionFRTSA is effective in enhancing speed, explosive power, flexibility, and strength, supporting policy integration of structured activity programs in rural schools.