Speedbags are small, dense punching bags that are commonly used in boxing and martial arts training. There are several other terms used for speedbags, such as speed balls, speed balls, or simply speedballs. Other synonyms for speedbags include speed sacs, speed bladders, and pears. Additionally, speedbags are sometimes referred to as swivels because of the mechanism that allows them to rotate on a mounting bracket. Speedbags are an essential tool for improving hand-eye coordination, dexterity, and timing, and are an important component in the training regimens of fighters and fitness enthusiasts alike. With so many different names used to describe speedbags, it's important to understand the terminology when seeking out this essential training tool.