The warm-up period before a workout allows the persons muscles to stretch out, and work up to the more intense workout, without hurting, tearing, or injuring. It increases heart rate, which loosens up joints, and increases blood flow to muscles, all which prevents the person from getting hurt.
Answer:
A sensor monitors the body's condition > The control center interprets the data and decides what action is necessary > the effector causes and action that returns the body to stable condition