It is one of the key tools in boxing gyms, but at home you can experience it if you enable a space.
Although hitting a sack has the main objective of building fighting skills, if you do it daily it also contributes to physical power, since you generate muscle and strength.
i force your body to work harder than it commonly does, they suffer microscopic tears, which heal thicker and stronger, like scars from a cut in your skin.
This is how resistance training builds muscle.
When you hit a training bag, it resists the force of your blow, building the muscles that struck.