While you wait, there have been some past answers provided to how those in ancient Rome (and other city-states) kept in shape:

• Were there any gym-like locations in Ancient Rome or Greece where people would go and workout?
• Ancient Workout routines
  • TheRazaman specifically touched on your question in that thread
• How did the ancient greeks and romans have such a detailed and accurate depiction of the muscles in the human anatomy?
  • This one might not seem connected and focuses more on the Greeks, but I think a few of the responses go into some details relevant to your question.