Slam Ball vs. Medicine Ball: Which Is a Better Strength-Training Tool?

Slam balls and medicine balls are both weighted balls you can use to make your workout more challenging. And no, they're not the same thing.

"The main difference between a slam ball and a medicine ball is the medicine ball will bounce back, while the slam ball will not bounce but simply land and absorb the impact," Cori Lefkowith, CPT, owner of Redefining Strength, an online fitness company, tells LIVESTRONG.com.

In addition, slam balls are usually a bit smaller and made of rubber (filled with sand), whereas medicine balls are typically bigger and often made of softer materials. The differences between the two are slight but should be considered to ensure you get the right equipment for your fitness goals.

Read on to learn the benefits and downsides of each.

Since the slam ball doesn't bounce, you can put maximum effort into every throw, toss and slam without fear of getting hit on the rebound. This makes it a great tool for developing explosive strength and power — especially if you focus on moving quickly and throwing the ball as hard and as fast as you can.

"This improves your mind-body connection and ability to recruit the correct amount of muscle fibers efficiently to perform the movement," Lefkowith says.

Unlike dumbbells or kettlebells, which are evenly weighted and come with handles to grip, slam balls are unevenly weighted with a sand filler and don't typically have handles. These features make slam balls a great tool for adding instability to your strength training. And incorporating instability into your routine offers many benefits.

"Slam balls will especially challenge your forearm muscles, as the weight in the ball will often shift," Lefkowith says. Working your forearm muscles will help strengthen your grip — a key indicator of longevity, according to a May 2015 study in ​The Lancet​.

All that sand shifting around inside the slam ball also fires up your core muscles as your body works to stabilize, Lefkowith says. And depending on what move you're doing, you may feel other muscles kick in to keep you balanced while the weight shifts.

Picking up the slam ball after every rep is a great way to build functional strength. In particular, the ability to pick up heavy, awkward objects off the floor.

"Many of the things we lift in everyday life are weirdly shaped or unevenly weighted — they're not barbells or dumbbells with perfect handles," Lefkowith says.

Plus, you'll get core work. "Whenever you use your body to pick something weighted from the floor, you must engage your core to facilitate the movement," Jakob Roze, CSCS, owner of RozeFit personal training, tells LIVESTRONG.com.

The slam ball's no-bounce feature is also one of its drawbacks. "Since there is no rebound, you'll have to pick up the ball from the floor and focus on your form again," says performance enhancement specialist James Shapiro, PES, a sports performance coach based in Los Angeles, California. This can make it tough to settle into a rhythm and limits how quickly you're able to complete your sets.

As we've noted, most slam balls have a filler that shifts around, making one side of the ball more weighted. "This is beneficial when slamming the ball because it keeps the ball from bouncing," Roze says. However, this may make it tough to perform other moves with the ball, he notes.

Because the slam ball won't bounce back when thrown against a wall, you'll need to recruit a partner for passing drills, like chest passes and scoop tosses, according to Lefkowith.

Thanks to the fact that medicine balls are lighter and bounce back after they're thrown, they let you complete several reps in rapid-fire succession.

As a result, medicine balls are the ideal tool for cardiovascular conditioning, Lefkowith says. They can also be used to add weight to plyometric movements and compound exercises to up the challenge, which helps you make continued strength progress.

A medicine ball will bounce off many surfaces, like floors and walls. This means you can perform passing drills like chest passes, half-kneeling tosses and scoop throws without a partner — just throw the medicine ball against the floor or a wall and catch it on the rebound.

Since the weight is more evenly distributed in a medicine ball than it is in a slam ball, you can perform a greater variety of exercises more comfortably and efficiently, like a "wall ball" — an exercise where you squat down while holding a medicine ball, toss it into the air and toward a target (usually a wall) as you stand up, then catch the ball and repeat.

Additionally, the partner toss may be better with a medicine ball than a slam ball. "Since the slam ball is weighted to one side, it could send the ball off-course if you're trying to throw it in a particular direction," Roze says. A medicine ball, on the other hand, is more likely to reach its intended target.

Medicine balls are typically larger than slam balls. "With a bigger diameter comes a harder time keeping it in position for certain exercises," Shapiro says.

Performing exercises that call for keeping the medicine ball close to your body (e.g., Russian twists, shot put throws) can feel exceptionally awkward.

Depending on the bounciness of the medicine ball, you may need to be especially cautious when slamming it against a surface, or you run the risk of getting hit in the face on the rebound. Or, it may bounce away, forcing you to chase after it. This can be a major drawback — not to mention a tripping hazard — in a crowded gym.

Slam balls and medicine balls are equally useful tools to incorporate into your workouts. The best option for you depends on your goals: If explosive strength and power is your focus, you may want to reach for a slam ball. If you'd rather develop strength and endurance, a medicine ball may be a better option.

Still, you can make either work for you through intelligent programming. "The great thing about the slam ball and medicine ball is they can both be used to improve conditioning and power," Roze says.

For example, you can use a slam ball to improve your endurance by easing up on how hard you slam the ball, which will allow you to work for more extended sets. Similarly, you can use a medicine ball to boost power by keeping your reps quick.