"What is the length of the preliminary approach run for juniors and seniors in javelin throwing, and what is the recommended body positioning during this phase?"
During this phase, the javelin is carried at head height, with the arm bent and the elbow pointing forward. The palm of the hand must face upwards to help the wrist, elbow, and shoulder relax, leading to an easy running action. The shoulders should be parallel to the run-up, and the hips are kept high with the body weight on the ball of the foot. The javelin should be lined up approximately parallel to the ground. The approach speed should increase constantly to the maximum controllable speed. The length of the preliminary approach run is as follows: Juniors typically use 4 to 8 strides long, finishing on the right foot, while Seniors use 8 to 14 strides long, also finishing on the right foot.