While waiting for other answers, you might be interested in these links from the Health page of the FAQ:

"How strong/muscular were ancient warriors? Did they know enough about muscle growth to be the same build as many athletes/bodybuilders now? When did humans start becoming adept at bodybuilding?" by /u/talondearg

'Did spartan warriors "work out" in the sense that athletes do today? What did they do?' by /u/Trhasyboulus

But this is not to discourage discussion. The rules state, "you are still welcome to ask your question if it has been asked before: you may get new answers from different people".