The purpose of cool-down exercises after a workout is to gradually lower the heart rate, promote muscle recovery, and prevent dizziness or fainting. Cool-downs help the body transition from intense activity to a resting state, allowing for the removal of metabolic waste products like lactic acid. Incorporating stretching into the cool-down routine enhances flexibility and reduces muscle tightness, lowering the risk of injury in subsequent workouts. Overall, a proper cool-down supports long-term athletic performance and overall physical health.