We’ve all been there: You walk into the gym, jazzed up on the idea of getting in a great workout, only to look around and see machines that are anything but obvious in terms of how to actually use them. Take cable machines, for example. Thanks to their adjustable nature (in which the cable can be positioned up top for movements like tricep pull-downs, or down below for bicep cable curls) and wide-set display, people often assume that they’re only to use one cable at a time. In reality, the reason there are cables on either side of the machine is so that users can stand in the middle to perform one of the most effective standing chest exercises of all: the cable crossover.

What is a cable crossover?

ACE scientific education content manager Chris Gagliardi explains that “the cable crossover refers to the hands crossing over the midline of the body and each other.” In other words, it’s all about standing square in the middle of a cable machine, with a cable in each hand.

Where some movements are designed with heavy weight and massive amounts of power in mind, Tonal coach Jared Rodriguez, founder of the Inspired Method, says that cable crossovers are all about creating highly-defined pectorals through slow and steady movement.

“The cable crossover is a chest isolation exercise meant to shred the inside and outside parts of the pectoral muscles,” he explains, noting that, unlike a typical cable chest fly, cable crossovers challenge the athlete by expanding their range of motion.

The benefits of a cable crossover

When it comes to chest exercises, most people’s first thought is barbell chest presses. While those are absolutely effective, Gagliardi says that cable crossovers effectively target the pecs at roughly the same level of muscle activation.

“Cable crossovers elicit about the same rating of perceived exertion (RPE) as the barbell bench press and pec deck machine,” he explains. “This means that when performing this exercise, it feels about as hard as performing exercises with a similar level of muscle activation.”

But that’s not the only reason that cable crossovers are an appealing exercise—they’re also great for your core. “The benefits of cable crossovers range from chest sculpting to full body stabilizing power,” Rodriguez explains. “Since your body is in a standing, split stance, our core muscles must be active during the entire range of motion.”

Since it requires so much core power—not to mention support from your shoulders, biceps, and triceps—Rodriguez recommends incorporating cable crossovers into the end of your workout so as to not burn out the moment you walk into the gym (or up to your home equipment, like the Tonal Home Gym, $2,995).

Beyond their muscular benefits, Gagliardi points out that cable crossovers are especially great thanks to their ease of set-up and changing the weight load. “Because this exercise requires a cable system, you are using a weight stack that allows for an easy transition in load and from one exercise to the next if performing circuit training or a superset,” he explains.

How to perform a cable crossover

Although cable crossovers are easy to set up in the grand scheme of weight equipment, it helps to know how to do so in the first place.

1. Start by adjusting the cables.

“Place the handles at a level that is aligned with your shoulders,” Gagliardi instructs. “Do not set the cable handles above the level of the head or below the level of the shoulder for this exercise.”

2. Tailor the weight.

Next, Gagliardi says to pick your weight. “Select an appropriate weight based on training experience, goals, and muscular fitness level,” he says.

3. Get into a staggered stance.

With your feet split (ie: with one slightly in front of the other), Gagliardi says to lean forward at the waist while keeping your spine stable and your back and head in a straight line. “It is important to lean forward while keeping the body aligned in a vertical position,” he explains. “You are not bending over at the waist making your torso perpendicular to your legs but are keeping your body aligned vertically while leaning over your lead leg.”

4. Perform the cable crossover.

Once you’re in position with your core braced, Gagliardi says to gently exhale and slowly squeeze your chest muscles to pull your arms forward until your hands come together in front of your chest. “Maintain the slight bend in your elbows, neutral wrist position, and stable alignment of your trunk throughout the movement,” he says, noting to pause momentarily before slowly returning to the starting position.

To further illustrate the proper form, Rodriguez says to imagine hugging a huge tree. “Then, maintain that same shape as you open back to your standing position,” he explains.

Notice how they don’t recommend actually crossing your hands over each other, but rather crossing the cables over each half of your body? There’s a reason for that. “Crossing the two handles above and below each other to come past the midline does little in terms of muscular conditioning, and there is a risk of injury of the hand when the handles pass so close to each other,” Gagliardi explains. “In other words, bringing the hands together at the midline of the body is just as effective as crossing the hands over each other and avoids the risk of injuries to the fingers and hands.”

5. And repeat.

For best results, Gagliardi says to perform two to four sets and opt for between eight and 12 reps if you’re hoping for improved power and strength; or between 15 and 25 reps if your goal is muscular endurance.

Cable crossover mistakes to avoid

When performing cable crossovers, there are a few things to keep in mind—and they play into each other.

1. Don’t rush.

As much as you may want to get the exercise over with, Rodriguez says that rushing through your reps can cause you to lose tension in your chest, to abandon proper form, and to forget to breathe throughout the moment. As such, he says to keep it slow and steady when performing the movement. “There’s a time to move fast and there’s a time to slow down,” he explains. “This ain’t a move to rush or race through. Momentum and strength are not friends. Work at a moderate pace in both the concentric and eccentric directions of this exercise. Slowing down doesn’t mean you get passive and relaxed. I still want you to bring your power. Just do it at a moderate speed.”

2. Maintain tension in the cables.

Even if you move with intention, it’s possible to be thrown off by the cables and weight, though. “An even bigger mistake is to let the weight control you when you should be controlling the weight,” Rodriguez says. “Don’t allow the tension of the cable to throw your arms back, force you off balance, or get sloppy—focus on starting and maintaining tension in your chest and arms. That way, momentum can never crash your gains party!”

3. Don’t forget to breathe.

“Our muscles and body need oxygen and when we’re so focused on the task at hand, sometimes we forget to breathe,” Rodrigues says. “The problem is, not only do we lose out on power that way but everything else in this move gets sloppy and fast.” With that in mind, he says to exhale while you squeeze your handles together (and if you choose to cross over) and to inhale as you open.