The Effects and Mechanisms of Endurance Training Using Different Gradual Load-Increase Protocols on Aerobic Endurance in Male Athletes Aged 14–16

INTERVENTION: Experimental group:The experimental group underwent unilateral compound training twice a week while continuing their existing endurance training. The training program employed a load ratio of "dominant side: non‐dominant side = 1:2," meaning the training volume for the non‐dominant side was twice that of the dominant side. This was done to intensify stimulation of the weaker limb and promote a catch‐up improvement in neural drive and strength output on the non‐dominant side.;Control group:none; CONDITION: Asymmetry between the limbs PRIMARY OUTCOME: running economy;Lower‐body explosiveness;Asymmetry between the limbs; INCLUSION CRITERIA: 1. Age range: 18–29 years old; 2. Some experience in marathon training, with the best marathon results meeting the corresponding amateur level standards; 3. Maintained a stable running volume in the past 6 months; 4. No significant history of musculoskeletal injuries; 5. Able to complete experiments like strength training, treadmill tests, and jump tests.