A method according to an embodiments includes administering at least two Cyclic Variations in Altitude Condition (CVAC) sessions to a mammal disposed in a pressure vessel unit. The at least two CVAC sessions each have a duration of at least twenty minutes. The at least two CVAC sessions each include a start point of ambient pressure at a delivery site, an end point of ambient pressure at the delivery site, and a plurality of atmospheric pressure targets executed between the start point and the end point. The administering is configured to treat at least one of loss of sensation and chronic pain.

A system for unweighting a user for an exercise session includes a framework having a plurality of connected frame members defining at least one surface for retaining a treadmill, and a substantially airtight chamber attached the framework extending upward therefrom when inflated. The treadmill has running surface, and the framework has a sealing surface disposed about the running surface. The substantially airtight chamber has an upper chamber portion defining a top opening operable for attachment to the user when extending through the chamber for the exercise session, a lower chamber portion below the upper chamber portion, and a removable sealing assembly securing the lower chamber portion to the upper chamber portion.

The present invention provides a differential pressure body suit with external support against body suit migration. In its preferred embodiment, such body suit may comprise a close-fitting, multi-layered suit sealed against a mammal's skin to contain the differential pressure, or a looser-fitting suit that bends at the mammal's joints with minimal force. External support means include either fixed or movable mechanical supports attached to the body suit, extraordinary air pressure levels for making the body suit rigid, or exoskeletons attached to the body suit, or a counter-force suspension cable adjustment system. A cyclic control system can turn the differential pressure condition within the body suit on and off on a selective basis to accommodate the movement of the legs of the mammal. This differential pressure body suit provides a portable and convenient system for, e.g., rehabilitating a skeletal joint injury or training the mammal for injury prevention or athletic performance or fat burning. The pressurization reduces the weight of the body to greater or lesser extents, and offloads the weight to the ground through the external support means.