An exercise machine includes a frame with foot pedals mounted thereon and a seat having an inflatable bladder whereby the user may undertake a cardiovascular workout and a core workout of abdominal and back muscles. A sensor may be used to sense the degree of compression of the inflatable bladder when a person sits on the inflatable seat whereby the internal pressure of the bladder may be adjusted accordingly. The frame may have two sections which are detachable so that one of the sections and the inflatable seat serve as a seating assembly when detached.