There are a wide variety of alternatives to using medicine balls. Popular alternatives include the following exercises.
free weights
barbells
bodyweight exercises
kettlebells
Free weights are often used in place of medicine balls because they provide a more comprehensive range of motion and allow you to target specific muscle groups.
Barbels are another popular alternative to medicine balls. Barbells are often used for similar exercises but allow the user to increase the amount of weight for the movement.
Bodyweight exercises are the most similar alternative to medicine balls because you can do all the same exercises in a similar form.
Kettlebells are a popular alternative to medicine balls because they offer a similar range of motion.