Person support apparatuses are disclosed. In one embodiment, a person support apparatus comprises a base frame and a primary support frame supported on the base frame. A carriage is freely translatable at least between a head end of the primary support frame and a foot end of the primary support frame. A support surface is supported on the carriage such that the support surface translates with the carriage. The support surface includes a support section which is collapsible in a length direction of the support surface. The support section may include an air bladder and a control valve fluidly coupled to the air bladder that regulates air pressure within the air bladder. The control valve has a normally closed position and a vent position, wherein the person support apparatus comprises an exercise configuration wherein the control valve is in the vent position and the air bladder is vented to atmosphere.
