Seeing this question about the oldest known exercise equipment, I remembered a scene from I, Claudius when Tiberius is working out with a medicine ball, so I thought that might be a good candidate. I began looking for verification that the medicine ball is as ancient as Rome or older.
At first, I thought had it: there are scores of websites with factoids roughly equivalent to the following (from a South African newspaper):
TODAY medicine balls come in a range of weights, sizes and funky colours but ancient drawings date the equipment to almost 3000 years ago, when Persian wrestlers trained with sand-filled bladders.
In ancient Greece, the physician Hippocrates is said to have stuffed animal skins for patients to toss for “medicinal” purposes – hence the name today of “medicine ball”.
These factoids are repeated by multiple US Patent Applications mention, the "Secret History of Balls", fitness blogs, this website selling medicine balls, and by a Reuters article published in various UK and US newspapers.
But I noticed a few things. First, the blurbs are very inconsistent about whether Persian wrestlers, soldiers, or sailors used medicine balls (and whether the Persian evidence is textual or pictorial). Second, just about every mention of the Hippocrates/Persia/Medicine Ball connection is from 2011 or later. Finally, no one cites a passage from Hippocrates or a classicist on the topic. The closest any article gets to citing an authority is a reference to "Deborah McConnell, master trainer at equipment manufacturer Life Fitness."
I tried text searches of the collected works of Hippocrates. I Google Image searched "Persian Medicine Balls", and then I spent some time on Google Scholar, but I can't find any mention of the Hippocrates or Persian connection. This is beginning to have the feel of an invented fact.
Prima facie it seems very plausible that ancient civilizations threw around heavy balls filled with sand, but is there any solid evidence that Ancient Persians or Greeks trained with medicine balls or that Hippocrates recommended as much?