Most any ancient culture used a form of Indian clubs for weapon training; as swords, maces, axes, battle clubs, etc. Used in Sumer, Egypt, Persian, Celtic, Roman, etc battle training. Even modern baseball players have a weight attached to their bats for practice swings. They could probably benefit from Indian club workouts.....just saying.
(had an opportunity to handle a original English two handed middle age broadsword, had to be 3 1/2 to 4ft long, if memory serves. Surprise actually how light it seemed and fairly easy to handle once getting adjusted to it.)
Indian clubs build up stamina (endurance & strength) as a excellent way to workout. Maybe they will catch on with the cardio freaks out there. If the out dated and awkward kettlebells staged a recent comeback, why not the productive Indian clubs.