Light and flexible is the name of the game here. A lot of mesh for breathability and Charged Cushioning® to help protect against impact. Just put them on and run for miles. -Performance mesh upper for lightweight breathability -Foam padding placed around your ankle collar & under the tongue for an incredibly comfortable fit & feel -Deluxe foam sockliner molds to your foot for added underfoot comfort -Charged Cushioning® midsole uses compression molded foam for ultimate responsiveness & durability -Durable outsole pattern for flex & traction