A Swiss ball, also known as a stability ball or exercise ball, is a large, inflatable sphere used for fitness and rehabilitation. Typically made of durable plastic, it comes in various sizes to accommodate different heights and exercises. The ball helps improve balance, core strength, and flexibility by engaging multiple muscle groups during workouts. In addition to fitness, the Swiss ball is often used in physical therapy to aid recovery from injuries. It can be incorporated into various exercises, such as sit-ups, push-ups, and stretches, making it a versatile tool for both beginners and advanced users.