crunning is crawling without the knees and running but with your hands. Mcarthy invented crunning. Crunning is better because they have a more slower version of crunning in Zhengzhou. it doesn't say anything about experts but Mcarthy thinks it is more affective because it puts emphasis on the shoulders and the arms which completes a full body workout. Zhengzhou does a simalar workout but they do it a little more slower. they do crunning because Mcarthy think it completes and is a full body workout.