It performs higher functions as interpreting feelings, emotions, learning, vision, reasoning, and fine control of movement. Brain is protected by the bones of the skull and cerebral fluid. It is a major organ in the body. It controls us to think and make decisions. It controls actions and reactions in us. It controls chemical reactions in the body through light muscle strengthening, light stretching, cardio exercise, and neck exercise. Eat and stay with a food program that should bring protein synthesis, amino acids synthesis, reduce stress on endocrine organs, let food digest before exercise, and supplement after meal as required to be a perfect human. Most importantly, a body must have antioxidants before a meal. 

Chemical reactions by the brain control the speed and accuracy of which people perform activities. A normal human would be able to perform thinking and physical activities with speed and accuracy. A not so normal human would not be able to perform the similar thoughts and physical activities with similar speed and accuracy. The advantage of knowing the difference between normal and not normal is avoidance of repetitive exercises which the body cannot control. In biology, any strenuous force exerts on the body system would create a shortcoming of growth. In physic, a body can build muscle mass and performance without exerts force on the body system and would be useful.