adidas have managed to squeeze an extra 9mm into the forefoot and heel of the Ultraboost 5X, giving a 2% increase in energy return, all while managing to get the overall weight even lower than before, thanks to an update to their legendary ultraboost foam, now called Light BOOST. All that extra foam gets held in form by a torsion system visible through the outsole, to ensure you have stability you need, as well as the plush and comfortable ride they are known for. Underfoot, continental rubber in high wear areas gives excellent traction and durability and surrounding the foot, a sock like fit of Primeknit hugs the foot for a comfortable hold, with a sleek, uncluttered style.