If you want to optimize your workout, you have to know your muscles. While most gym-goers tend to focus on their chest, shoulder, tricep, and bicep muscle groups, you may be surprised to learn that the strongest muscle in the human body, pound for pound, is found in our mouth. The masseters are facial muscles that play a major role in the chewing of food. People who overwork the masseters by grinding their teeth during sleep often develop squared jaws.  
Your body is home to more than 600 muscles and, contrary to popular belief, all those muscles can only pull and cannot push. The only reason your arms can “push” is because all the muscles in the back of the arm “pull” the elbow. An infographic from Decibel Nutrition provides information on some of the best exercises for targeting each of our body’s muscle groups.
Any effective workout routine includes two types of exercise: compound movements and isolation movements. Compounds movements include any exercise that utilizes more than one major muscle group, such as bench press, squats, and deadlifts. Isolation movements, on the other hand, include any exercise that only uses one major muscle group, such as flyes, bicep curls, and tricep extensions. Finding out which compound and isolation movements work best for you is your key to an efficient workout. 
 Optimise Your Workout
Source: http://www.medicaldaily.com/pulse/know-your-body-how-master-all-600-muscles-found-your-body-321876?utm_content=buffer308a0&utm_medium=social&utm_source=facebook.com&utm_campaign=buffer