Second: the essentials of arm-to-arm running. The swing arm should move back and forth with the shoulder as the axis, and the range of left and right movement should not exceed the midline of the body, and the fingers, wrists and arms should be kept relaxed.
The elbow angle is about 90 degrees. Raise the elbow joint of the rear swing arm as much as possible, then relax the front swing and lift it higher and higher as the action accelerates.
Third: the posture of the trunk and buttocks should be upright from the neck to the abdomen, not forward or backward, unless the trunk can lean forward slightly when accelerating or uphill.
Keeping the trunk upright during running is helpful for breathing, maintaining balance and stride, and the trunk should not shake from side to side or fluctuate up and down too much. When your legs swing forward, your hips should take the initiative, and you should pay attention to the rotation and relaxation of your hips when running.
Fourth: the hips should be tense and the leg lifts should be moderate. Hip is the center of body strength and the strongest muscle of human body. Keeping the correct body posture can make the hips highly tense and give the body a continuous motivation.
If you bend forward or lean forward too much during running, your pelvis will also lean forward, which will put pressure on your lower back.
For fitness runners, leg lifts should be moderate and should not blindly pursue stride and frequency. They should choose an appropriate stride and try to keep each foot directly under their bodies.