If your shoes are symmetrically shaped (taper in towards a point in the middle at the toe-box) then you have to to avoid doing even more damage to your feet. Often time up to 3 sizes too big to allow the toes to fully splay under load. Another benefit of functional footwear is that you don't have to wear them too big. However, we do recommend that you have at least a thumbnail distance from your toes to where to toes end. Your foot expands up to 20-30 square centimeters when you put more weight through it during walking or running.