Abstract: A comfort sole arranged to be mounted in a shoe extends from the heel portion of the shoe to approximately the arch. The sole has a resilient upward curved portion intermediate the sides thereof in the area of the heel portion to form an air chamber between it and the sole of the shoe. This curved portion is arranged to flex up and down due to lifting and lowering of the person's foot while walking or running to pump air from the air chamber around the foot. The comfort sole has a cross sectional shape including thickened side portions which provide good fit and good support of a person's foot. A portion of the shoe may be recessed under the upward curved portion to increase the size of the air chamber.