A method and apparatus for cyclic variations in altitude condition that allows a user to rest in a pressure vessel while undergoing rapid variations or transitions between simulated altitudes. The pressure vessel comprises a blower to generate negative pressure, and a proportional valve to allow air back into the pressure vessel in order to relieve the negative pressure. An on-board interface, kiosk controller and master controller are all in electrical communication with each other in order to enable a user to implement a program of cyclic variations in altitude conditioning that is suitable to the specific user, and enables an operator to bill the user for such services, as well as to allow the user to use a different pressure vessel without re-entering data, so long as such data was originally entered and stored, and the different pressure vessel is in electrical communication with the master controller. A user sensor monitors the user during a session, such that the program may be modified or replaced with another program in real time, according to the users needs.
