A punching bag is a durable bag designed for training in various combat sports, such as boxing and martial arts. It is typically filled with materials like sand, foam, or water to absorb impact. Punching bags come in different shapes and sizes, including heavy bags, speed bags, and double-end bags, each serving a specific purpose in training. Using a punching bag helps improve strength, speed, and coordination. It allows athletes to practice their punches, kicks, and footwork in a controlled environment. Regular training with a punching bag can enhance overall fitness and provide an effective cardiovascular workout.