Medicine balls are designed to improve your strength, power, endurance and functional fitness by adding resistance to strength training and plyometric exercises. To match the demands of different exercises along with different strength levels, medicine balls come in a variety of shapes, sizes and weights ranging from one to 50 pounds. Choosing the proper weight of the medicine ball is determined by the type of exercise being performed, your individual strength level and the number of repetitions you complete.
According to the American College of Sports Medicine, the proper medicine ball weight for you depends on the ball's effect on your speed of movement, accuracy, control or range of motion. When the medicine ball is too heavy, your motor skills and stamina decline resulting in poor form and technique that can eventually lead to injuries.
Plyometrics and Strength Training
Plyometrics and strength training exercises commonly involve using medicine balls to increase the intensity of exercise for power, speed and strength development. For power training exercises, the weight of the medicine ball should be about 30 to 50 percent of your one repetition maximum for a similar weight training exercise. For multi-joint exercises such as the overhead throw, the medicine ball must be large enough to handle comfortably with both hands while recruiting all of the major muscle groups involved in the movement
For abdominal training exercises, the overall size of the medicine ball should be smaller and lighter so you can maximize speed and technique. Choose a weight that you can perform the desired number of repetitions without losing control or sacrificing technique. You could typically choose a heavier weight for abdominal exercises where you hold the ball close to your body, but use a lighter ball when the ball is held away from the body.
As your strength increases, you can also increase the weight of the medicine ball. Always start out with lighter medicine balls to learn the proper form and technique before increase the weight. This gradual progression is commonly referred to as the principle of progressive overload that is associated with becoming stronger and improving movement control. Choosing the proper medicine ball along with gradually increasing the weight is essential for maximizing workout results while preventing injuries.