Salomon S/Lab Ultra Glide - Ultra Trail Marathon ShoeYou can't trade out for another runner at mile 70 so why should you wear a shoe that can't go the distance and duration you're running? Salomon realized there was a need for a shoe that can hold up to a 30 to 40 hour ultra marathon so they created the Salomon S Lab Ultra Glide. Designed specifically for runners who run an ultra between 30 to 40 hours. Details "So how does as shoe hold up to 30 to 40 hours during an ultra marathon" you might be asking.