From medicine balls to modern shipboard gyms

How did exercise equipment aboard ships evolve from its earliest use to today?

It progressed from simple medicine balls to normal commercial gym machines, while earlier sailors often got their exercise from the ship's labor itself.

Heavy medicine balls are identified as an early form of dedicated shipboard exercise equipment. Modern ships can carry the same commercial exercise machines found in gyms ashore, with Technogym equipment given as a recent example. For much of the age of sail and steam, routine shipboard work itself imposed heavy physical demands. Later sailing ships mechanized some sail handling, which the discussion distinguishes from fully automating it. The work could still damage sailors' hands, feet, knees, and backs.