The plastic exercise balls were first developed in the 1960s for physical therapy but have since been used in gym workouts to rev up traditional push-ups, sit-ups or yoga moves. The idea is for the ball's instability to improve a user's own stability, coordination and posture. The same concept seems to work with a growing number of schoolchildren across the country, according to research, but with an added benefit — it keeps kids engaged during class.
Stability balls are one of a number of types of balls you'll find in the gym. Medicine balls are weighted balls, usually about the size of a basketball. Medicine balls are used in strength training, rehabilitation and plyometric training. You can also find 7- to 9-inch inflatable plastic exercise balls to use during a variety of abdominal and Pilates-style exercises. Using a large-size ball increases your range of motion during these exercises and enhances your results. Small weighted balls that fit in one hand -- usually between one and five pounds -- are also available at some facilities. Use these balls to add weight to Pilates and yoga upper-body and core exercises.
You can get a plain, clear plastic exercise ball for your pocket pet, but there are several fancier options, like colored balls and even glittery models. The Dazzle Run-About Exercise Ball adds some glitz to your hamster, gerbil, mouse, or rat's workout.