1. Muscles grow while you sleep. All that hard work you put in at the gym pays off while you sleep. Without enough deep sleep, you will definitely not see the desired results.

2. Muscles make 85% of your body heat. When muscles contract, they give off heat which helps in keeping you warm.

3. It's easier to gain muscle than lose it. It takes twice as long to lose new muscle as it does to build it.

4. Muscle burns more calories than fat. Your metabolic rate (the number of calories you burn while resting) is influenced by your body composition. Muscle burns more calories than fat so if you are more muscular you burn more calories.

5. Approximately 40% of your body weight is muscles.