Dear Nina Sakura:

Of course, aerobic exercise is healthy in every way I can think of. I much prefer fast walking because when you run all your weight (and extra weight) drops on one knee, then on the other, again and again, and can injure the knees. This is because your whole body is in the air again and again before all the weight falls on this and the other knee. Injuries are frequent when running, not so in fast walking. Fast walking is definitely aerobic (especially on incline, so you can make it as difficult as you can stand it) and safer.

anita