What is the best thing to fill a punching bag with?

The best thing to fill a punching bag with is a combination of materials that provide an optimal balance of weight, density, and resilience. Here are some of the best fillers for different types of punching bags:

1. Traditional Heavy Bags: These are normally filled with shredded fabric or clothes. You can use old clothes or blankets, which are a cost-effective and eco-friendly option.

2. Water Bags: These bags are filled with water and are suitable for those who want a realistic feel as they punch. They also offer a greater degree of resistance and give better feedback during training.

3. Sandbags: These bags are great for building strength and endurance, they are usually filled with sand but can be filled with other materials like sawdust, beans, or clay.

4. Synthetic Materials: You can also fill punching bags with synthetic materials like foam, rubber, or gel. These materials offer better shock absorption and reduce the risk of injury while punching.

Ultimately, the best filler for a punching bag depends on your personal preference, training goals, and intended use. It's important to choose a filler that provides the right amount of resistance, support, and durability to suit your needs.