Salomon put their race caliber EnergyFoam+ inside an EnergyFoam carrier to create a stable yet bouncy experience. The relieveSphere outsole is designed to create pressure points underfoot to make the shoe more comfortable for longer distances. I’ve had a chance to test the shoe in snow, sand, and trail. And I’d say it does a fine job in each, although depending on the pace you want to race, I’d say it’s best suited for firmer terrain. It’s the tallest stack Salomon has ever put in a shoe, and it’s a ride that this road runner finds cushioned but capable. This is also the first time I’ve enjoyed using the lace garage. If I were to use this for very long races, I might size up (unless Salomon has always fit you very well in the past).