This type of Nike Running free shoes introduces the comfort for the feet of users. During the year, 2001, NSRL accumulated pieces of information about the exercising type without shoes. Based on the systematized judgment and study, they figured out that running with barefoot holds the elasticity of stems and muscles of feet. Due to the availability of Nike free, the users can make their dreams true nowadays. German Sport University Cologne verified the fact during the year of 2003 and 2004. Due to Nike Free, the feet and ankles might be more supple and powerful. At the same time, the shoes can make the muscles of feet.