A punching bag is a sturdy bag designed to train striking techniques.
Between the various types of punching bag, we can highlight the main:
• Speed bag: it is a small, air-filled bag anchored at the top to a rebound platform parallel to the ground. Its goal is to focus on faster hand speed, timing and coordination. A speed bag helps a user learn to keep his hands up, improve his hand-eye coordination and shift weight between feet.
• Swerve bag: almost similar to speed bag. The bag size shape and material may be different and a cable system is attached to the ceiling and a clip on the floor. The harder and faster they are hit, the more they rebound and react in different motions of angles, giving greater practice to the fighter.
• Heavy bag: it is a large, cylindrical bag, usually suspended by chains or ropes. An user can deliver blows with full power and speed, training his strength and endurance. When striking, it is important to keep one's joints stacked (using the knuckles of the index and middle fingers).
• Body opponent bag: It is a body-shaped training aid, made primarily of synthetic materials.
A heavy bag is usually covered with leather and filled with grains, sand, rags or other material, and hung horizontally from the ceiling, affixed to a stand or mounted on a weighted pedestal.
It should absorb the impact of blows, without causing harm to the user. To avoid injury, hand protection is highly recommended (boxing gloves, bag gloves, training gloves, hand wraps).
Heavy bag allows to develop raw power and combinations by punching and kicking multiple targets at various heights and locations, unlike makiwara where striking is done at a specific spot.
A boxer usually trains delivering fast and hard punches. He does not search to strike pushing the bag, but hitting it with snapping punches, where the force of impact bounces the fist back.
Some claim that training with punching bag and makiwara helps to develop punching skill to the highest level.