Medicine Ball Slams

What medicine ball slams actually train

A medicine ball slam is a power exercise where you lift a heavy, non-bouncing ball overhead and throw it into the floor in front of you as hard as you can.

The training effect is power and coordination. You are learning to produce a large amount of force quickly through a sequence that starts at the hips and finishes at the hands. That is worth training and it is not the same as training for size.

Muscularly, the abdominals and obliques do a great deal, since violent trunk flexion is what drives the ball down. The lats contribute strongly through shoulder extension, which is why a hard slam leaves your back feeling worked. The hips extend at the top and flex through the throw, and the shoulders and triceps guide the ball rather than powering it.

There is a second component people forget to count. Half the repetitions in a slam set are picking the ball up off the floor. Do fifty slams and you have also done fifty light deadlifts, which is fine if you hinge and a slow way to irritate your back if you scoop.

What slams will not do is build muscle. The load is light, the movement is fast and the resistance disappears at the moment of release, which means no eccentric loading at all. Schoenfeld and colleagues found a dose response between weekly hard sets and hypertrophy, and a slam is not a hard set of anything in that sense.

They are also not the fat loss tool they get sold as. The effort is high for the few seconds it lasts, which is not a reason to expect anything that total weekly activity would not deliver more reliably.

Used as short, high intent sets before or after your main work, slams are genuinely good. Used as a twenty rep burnout, they are just tiring.

Setting up and executing

Stand with the feet hip to shoulder width and the ball in both hands. Check that you have a dead slam ball rather than a bouncy medicine ball, because the alternative arrives back at your face.

Brace the abdominals and lift the ball overhead, rising onto the toes and extending fully at the top.

Snap the hips and trunk forward to start the throw, then pull the ball down hard with the arms and lats.

Release so the ball hits the floor just in front of your feet, and follow through into a hinge rather than stopping the arms abruptly.

Squat or hinge down to collect the ball with a flat back, reset your stance, and throw again with the same intent as the first rep.

The mistakes that cost you the most

Throwing with the arms only is the fault that removes the point of the exercise. A slam should start at the hips, travel through a stiff trunk and finish with the arms. If your shoulders are doing everything, you are performing a slow triceps movement and calling it power training.

Using a bouncy ball is dangerous rather than merely inefficient. Proper slam balls are filled to be dead on impact. A traditional medicine ball rebounds, and it rebounds towards your face.

Long sets with fading intent are the most common programming error. Power output falls quickly, and by the sixth or seventh throw most people are moving the ball rather than throwing it. Refalo and colleagues found that stopping short of failure produces comparable hypertrophy to training to failure, and for power work the logic is stronger still: the reps after the quality drops teach you to move slowly.

Rounding the back to pick the ball up is where slams actually cause problems. Cholewicki and colleagues measured lumbar loads during lifting and found spinal position has a large effect on compression, and you are lifting from the floor many times in quick succession while breathing hard. Hinge.

And treating slams as ab training is a category error. The trunk works, but you cannot load or progress a slam the way you can a weighted crunch or an ab wheel rollout.

Sets, reps and rest by goal

Keep the sets short and the intent high.

For power, which is the honest reason to do them, five sets of three to five throws with two minutes rest. Every throw maximal. That is the version that produces something no other exercise in your programme does.

If you are using them as part of a muscle building phase, four sets of six to eight with ninety seconds rest, placed either as a warm-up before pulling or as a finisher afterwards.

In a fat loss phase, six bouts of twenty seconds of continuous slamming with a minute of rest is a reasonable conditioning circuit. It is not doing anything special for body composition that a bike interval would not, and the specific exercise matters much less than your total effort over the week.

Progression here is about output, not volume. More sets of the same quality, not longer sets of decaying quality.

Where it fits in your split

Early in a session as power work, or at the end as a finisher.

On push, pull and legs, slams sit naturally on pull day, since the lats do a lot of the work. On a bro split they suit back or abs day. On an upper and lower split, put them early in a full body or upper session. If you have a slam ball at home, they are one of the better things to do with limited equipment.

Placing them first respects what they are. Three sets of five hard throws before you deadlift takes three minutes and warms up the pattern nicely. Placing them last is fine too, as long as you accept that you are then doing conditioning rather than power training.

Two or three sessions a week is easy to recover from, since there is no eccentric loading and very little soreness.

Variations worth knowing

The rotational slam, throwing the ball down to one side, adds a rotational demand through the trunk and is arguably the more useful version for anyone who plays a sport.

The overhead throw for distance sends the ball forward rather than down, training the same pattern with a longer acceleration and a clearer measure of output.

The wall ball, a squat into a throw against a wall, is really a conditioning exercise with a power element attached.

A chest pass against a wall trains upper body power horizontally, which is a genuinely different quality from a slam.

The kneeling slam removes the leg drive and forces the trunk to produce more of the force, which is a useful way to expose an arm dominant throw.

And the single arm slam adds an anti-rotation demand and shows up side to side differences that the two handed version hides completely.

What the evidence says

McGill's work on core training argues that the trunk transfers force between the hips and the upper body, and that stiffness matters more than trunk movement. A slam demonstrates it: the hips produce the force and the trunk decides how much reaches the ball.

Escamilla and colleagues measured activation across a wide range of commercial and traditional abdominal exercises and found large differences in trunk demand, supporting the point that the trunk can be trained deliberately and that a slam is not the most controlled way to do it.

Marchetti and colleagues examined abdominal activation during isometric ab wheel rollouts and found high demand in positions resisting trunk extension, a useful contrast: the rollout loads the trunk in a way you can progress precisely, while a slam does not.

Lehman and colleagues measured latissimus dorsi activation across weight training exercises and found it depends strongly on arm position and pulling direction, which explains why pulling the ball down from overhead involves the lats heavily.

Cholewicki and colleagues measured lumbar loads during heavy lifting and found spinal position has a large effect on compression, which is the reason to hinge rather than scoop between reps.

Schoenfeld and colleagues found a dose response between weekly hard sets and hypertrophy, which is why slams should not count towards muscle building volume.

Refalo and colleagues found that stopping short of failure produces comparable growth, and the same reasoning applied to power work argues for ending the set as soon as throw quality drops.

Common questions

Do slams build abs?

They work the trunk hard, but they cannot be loaded or progressed properly, and the resistance vanishes the moment you release the ball. For abdominal development, weighted crunches and ab wheel rollouts progress far more cleanly. Slams train the trunk to transmit force quickly, which is a different and useful thing.

How heavy should the ball be?

Light enough that you can throw it fast, so that each rep looks explosive rather than laboured. If the ball slows your throw down noticeably it is too heavy, because speed is the quality you are training.

How many reps per set?

Three to eight, depending on why you are doing them. Beyond that, power output drops and you are training slow movement. If you want a longer conditioning set, recognise it as conditioning rather than power work.

Can I use a regular medicine ball?

No. Traditional medicine balls bounce, and a bouncing ball thrown at the floor at full speed comes back up at your face. Use a dead slam ball designed for the purpose. It is the one piece of equipment advice here that is not negotiable.

Are slams good for fat loss?

Only in the general sense that any hard activity contributes to your total energy expenditure. Feeling violent does not make them more effective than a bike interval or a longer walk. Choose them because you enjoy the intent.