The phrase “balls to the wall” does not, against all expectations, have anything to do with testicles. Instead it derives from the world of military aviation and the handles on the throttle control levers, which are ball-shaped. To achieve maximum power pilots would push these balls forward as far as they went, to the cockpit wall. Hence “balls to the walls”, signifying all-out effort.

Coincidentally, all-out effort is what’s required to get through a session of wall balls. This savage compound exercise, beloved of the CrossFit community, is second only to the burpee for inducing muscle-aching exhaustion.

The whole body takes a beating with wall balls. The squat part of the exercise focuses on the lower-body muscles – your quads, glutes, calves and hamstrings – before the throw section powers up your chest, back, shoulders and arms. The entire movement also works the core and gets the heart pumping.

Doing wall balls quickly becomes a race to see what stops you first – screaming muscle pain or lung-busting exhaustion. It’s worth the effort though, because this exercise will make you functionally fit, increase your VO2 max (put simply, how efficiently your body uses oxygen) and improve the way you move – in life and sports.

“Wall throws require you to go into triple extension, where there is movement at the ankle, knee and hip joints, which will improve your ability in all activities and lifts that require speed, power and hip drive,” says Jack Lovett, owner of Spartan Performance and two-time British strongman champion. “To fully benefit you must perform the throws as explosively as possible. You don’t need to use a heavy med ball. Even my stronger athletes improve greatly with a 3kg ball, because it’s the speed of movement that matters most.”

How To Do Wall Balls

First you need to select your medicine ball. The weight recommended in CrossFit workouts is usually 9kg for men but you can adjust it to suit your fitness. If you are working out in a CrossFit box there will usually be a wall with heights marked, so you can try to throw your ball to a consistent level. If so, shoot for ten feet.

Once you’ve sorted your ball and your wall, hold the former up to your chest and face the latter. Drop into a squat until your thighs are at least parallel to the floor. Then push up through your heels and maintain that momentum to throw the ball against the wall. Catch the ball on the rebound and immediately drop into another squat. Make sure you don’t stand too far away from the wall – you don’t want to waste momentum and power by throwing the ball too far forward and leaning over to catch it.

Do ten to 15 reps for three sets or build them into a circuit – simply try to cram as many reps as possible into the interval prescribed. Or you can take a lesson from CrossFit classes and build them into a simple pyramid workout with another exercise, doing 21 reps of each, then 15 and finally nine. For example, you could do wall balls and burpees, completing the whole thing as fast as possible. You’d have to be insane, but you could do that.