Exercise apparatus simulating mild to high altitude environments

A personal physical conditioning system, for a single, full-size human subject, has a sealable chamber that is configured to allow entry therein and occupancy thereof by the entirety of the single, full-size human subject and to allow the subject to exercise in a standing position using an item of physical conditioning equipment entirely contained within the sealable chamber. The system also has a ventilation system, including a pump, operable to change air in the sealable chamber and to establish, within the sealable chamber, a desired non-zero air pressure level of less than 1 atmosphere and down to pressure conditions substantially equivalent to an elevation of 25,000 feet above sea level. Related methods are also provided.