Are you an avid crossword solver but get a little stumped every now and then? Well you've reached the right place! Here we will help you find the answer to the clue Working on one's muscles from Universal crossword. Once we've looked for any additional hints from inside the Universal crossword puzzle and gathered any other information that can help us find the answer to the clue Working on one's muscles, we can finally conclude that the possible answers for the clue Working on one's muscles are: