There are several synonyms for the popular fitness equipment known as exercise balls. These include stability balls, yoga balls, Swiss balls, balance balls, fitness balls, and gym balls. Each of these names describes the same type of large, inflatable ball used for various exercises and stretches. Exercise balls are commonly used in strength and conditioning workouts, rehabilitation exercises, Pilates, yoga, and other fitness practices. They are especially effective for improving balance, stability, and core strength. Whatever you call them, exercise balls are a versatile and convenient tool for incorporating full-body workouts into your fitness routine.