Double Grip Medicine Ball

Medicine balls, also commonly referred to as gravity balls or fitness balls, typically have a standard size of approximately 14 inches. The outer layer of a medicine ball is usually made of nylon covered with leather or vinyl, and the interior is filled with objects to provide weight. Medicine balls with an outer layer covered in vinyl are typically filled with sand and are not suitable for exercises requiring bounce. Some medicine balls have a semi-spherical core made of high-density material, with varying thicknesses, that appears to be integrated with the outer rubber surface. Other medicine balls have an outer layer consisting of a thin rubber bladder and a thick rubber layer. These designs enhance the ball's bounce performance. The outer rubber layer is also specifically designed for easy grip. Over time, if the medicine ball comes into contact with rough surfaces, it is prone to wear and tear. Other types of medicine balls include those made from gel-filled polyvinyl chloride balls or solid polyurethane. The materials vary depending on the design weight and density.

The medicine ball is one of the oldest methods in strength training. The earliest recorded history of medicine balls dates back nearly 3,000 years to Persian wrestlers using sand-filled pouches for training. In ancient Greece, the renowned physician Hippocrates had his patients throw medicine balls filled with sand and wrapped in animal fur to achieve preventive injury, injury recovery, and rehabilitation effects. Until the late 19th and early 20th centuries, "health" and "medicine" were synonymous terms. The so-called "Four Horsemen of Fitness" refer to dumbbells, bottle bars, dartboards, and medicine balls. This is the origin of modern medicine balls.