在做任何困难的运动如跑步之前，腿、手臂、背部和脖子要有充分拉伸。
You need to stretch your legs, arms, back and neck before you do any difficult activities like running.
为了对这种将腿提离地面的作用力作出反应，骨头会拉伸各种骨细胞，并强迫它们适应，通常是透过增加细胞，这导致了骨头密度变得更高。
It bowed in response to the forces moving up the leg from the ground, stretching the various bone cells and forcing them to adapt, usually by adding cells, which made the bone denser.
你可以先拉伸一条腿，然后换另外一条腿，或者将手从一边移动到另外一边。
You can vary this exercise by stretching first one leg, then the other, or by moving your hand positions from side to side.
应用推荐