Do u know we take one step by working 200 muscles in our body? Yeah, its depending on how we divide up muscle groups to take a single step use of 200 muscles.The muscles are the most dense thing in human body & its weighs more than fat.When we start to work out we lose weight at the beginning (losing fat), but then start to gain weight (muscle). That’s a many work for the muscles considering about 10,000 steps in a day.