A warm-up routine is essential before exercising as it prepares the body for increased physical activity. It raises heart rate, improves blood circulation, and loosens up muscles and joints, reducing the risk of injury. Additionally, warming up can enhance performance by preparing the body physiologically and mentally. It typically includes movements that mimic the exercises to follow, gradually increasing in intensity. This progressive approach helps improve flexibility and promotes better muscle elasticity, ensuring that the body is ready for the demands of the workout ahead.