1. Muscles make up 40% of your total body weight
2. It takes half as long to gain muscle than it does to lose it
3. The smallest muscles are found in the middle ear
4. To take one step, you use 200 muscles
5. Muscles cannot push
6. Humans are born with all the muscle fibers they will ever have
7. Your tongue is the strongest muscle in your body
8. It takes 17 muscles to smile and 43 to frown
9. When you're cold, your muscles contract involuntarily
10. The only muscle that never tires is your heart