A custom foot bed involves molding the bottom of your foot and building a foot bed which best suits the bottom of your foot. This can include shaping it to help my nerve problem and it also can help out skiers with flat feet or high arches. I have the latter and the resultant was a foot bed that has a better arch than my running shoes. Because of the dramatic change there was a breaking in period for comfort, but the performance improvement was immediate. When flexing my foot, the first movement would be to flatten my high arches which delays the reaction. Now all movement results in results. How fast? Early on, I caught my edges so well, I went into such a sharper turn, it almost turned me off of the edge of the slope. But don't get me wrong, it's a good thing and I love what it has done for my skiing.