a bladder construction which is semi porous such that ventilation is provided within the shoe while at the same time the bladder is pressurized to a selected level and maintained there by the valve 26 for the sake of good fit in another alternative embodiment the bladder is made of a material which is semi permeable allowing moisture to migrate from the foot area into the bladder while at the same time air from the bladder can escape only through the vent valve 26 in such a construction pressurization is maintained for fit of the shoe to the user and dehumidification in the foot regions is provided such shoes which provide for any or all of foot ventilation foot drying and adjustable fitting of the shoe to the user can be highly advantageous for people who must do considerable amounts of walking standing or running for example those in military service mail delivery personnel messengers etc it should further be understood that the pump 12 need not be located in the heel region of the shoe but may also be placed in the sole area for example near the ball of the foot basically the pump must be located where the user 39 s motion and weight are available for actuating the pump in performance of its air delivery task applications of the concepts contained herein to other fields for example for automatically maintaining the pressure in automotive vehicle tires are entirely possible it will thus be seen that the objects set forth above among those made apparent from the preceeding description are efficiently attained and since certain changes may be.