Zander's mechanical horse was an early version of the Stairmaster, a contraption for cardiovascular fitness designed to imitate a "natural" activity. His stomach-punching apparatus evokes contemporary "ab-crunching" machines. What makes Zander so important, for anyone trying to trace the Cybex family tree, is what happened when his machines, created in a European cultural context, immigrated to the US in the early twentieth century. They are prototypes of the workout equipment now ubiquitous in American life.
Source: cabinetmagazine.org