You've seen the medicine balls at the gym. You walk right by them and go straight to the dumbbells [1]. We get it — they're not as popular, and they're kind of intimidating. How the hell do you even use one? Try this amazing exercise called a ball slam.

It's one of the ultimate total-body strengthening moves [2] that will also get your heart rate zooming and burn calories. It may not look that hard, but once you do a bunch of reps in a row, you'll see why this is a popular exercise you'll find in CrossFit workouts [3] — it's intense and effective.

When you're first learning this move, go for a lighter medicine ball, such as 4kg. Make sure it's nonbouncy so it doesn't fly up and hit you in the nose. As you feel more comfortable and get stronger, you can eventually go for anything up to 18kg. Be prepared to work your legs, butt, arms, and core. Here's how to do the move.

• Stand with your feet shoulder-width distant apart with the medicine ball on the floor in front of you.
• Squat down and pick up the medicine ball, keeping your head up and trying not to round the spine.
• Stand up, lifting the medicine ball above your head, fully extending the arms straight above you.
• Forcefully slam the ball down on the floor as hard as you can. If the ball is light enough, catch the ball as it bounces slightly off the floor.
• This counts as one rep.
• Cycle through three sets of 12 to 15 reps.