Unlike the Nike Free 5.0, the Nike Free 3.0's upper (the part of the shoe that covers the top of the foot) includes a large patch of mesh and a tongue. The mesh lets the 3.0 breathe better than the 5.0. The tongue is thinner than any other material on the shoe, and rarely stays in place. Since the 5.0 did not have a tongue, this was not a problem. The 3.0 also features the solid heel that the 5.0 lacks. The solid heel makes the back half of the 3.0 stiff. A person who has flat feet quickly finds that the stiff heel rubs the ankles, causing discomfort. The Lycra heel on the 5.0 does not have this problem.
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