Punching bags are usually cylindrical and filled with various materials of suitable hardness. The most common filling inside a punching bag is shredded textile material like clothing, which is shredded then stuffed into the bag in stages. Shredded material is perfect for a punching bag for a number of reasons. The first reason is that the material allows for enough cushion while punching to not damage your hand/wrist. This combined with a good set of gloves and hand wraps means the boxer can have the best workout or training session possible. The next reason is that shredded material is perfect for punching bags is that it does not require additional manufacturing. In some cases, the material can be used from recycled textiles to reduce environmental impact.

Another variation of a standard punching bag is one that is filled with shredded foam and shredded material, which gives the bag slightly more cushion or rebound while punching. Another variation of this is a punching bag that has foam liners that can vary in thickness. All free-standing heavy bags are typically solid foam with a plastic pipe core. This is so the bag does not warp or slump over when you start hitting it. The foam stays rigid enough to hold itself upright.

Other materials that can be used to fill a punching bag include:

• Sandbags: Sandbags are used to increase the weight of the bag, but its important not to completely fill a bag with sand. Each sandbag will weigh around 250 - 500 gms so you can add as many bags as you would like to make it heavy enough for you.

• Sawdust: Sawdust is rarely used to fill a punching bag, but some people have used it and were happy with it. However, its better to stick to cotton waste and sandbags as these are the best ways currently that you can fill a punching bag.

• Old Clothes: If youre a beginner whos looking for a lightweight punching bag, you can just use clothes or scrap fabric as a filling. Otherwise, youll want to add some sand or sawdust to your bag to increase its weight and resistance. When filling a punching bag with clothes, start by cutting off any zips or buttons so they wont damage the bag. Fold your clothes into squares, then fill up the bag from the bottom. As you work, knock in any lumps with your hands to ensure the filling is evenly distributed.

Its important to note that filling a punching bag with just sand or sawdust will make it too heavy and dense. Instead, add it in addition to clothes or fabric.