How to Isolate the Chest With Bench Press

Because the bench press is a compound chest workout, you can't truly isolate your pecs — your shoulders and triceps will always help out to some degree. However, there are some steps you can take to shift more of the focus to your chest muscles.

It's true that your pectoralis major — the big, beefy chest muscle that's evident on muscular men — is the primary mover during a bench press. But it's far from the only muscle working: When you do a bench press, your triceps and anterior deltoid, or the front of your cap-like shoulder muscle, both kick in powerfully as well.

Before digging into how to (somewhat) isolate your chest, here's a look at proper bench press form. To do this, you need a solid weight bench, a barbell and a rack that's appropriately set up to hold the barbell, positioned at the head of the bench. Ideally, you should have a spotter too — especially as you're first getting used to this exercise.

1. Lie face-up on the bench, scooting toward the bar until your eyes are almost level with it. Ideally, your feet should rest flat on the floor to either side of the bench, giving you a wider base for stability.
2. Take the bar in an overhand grip, hands slightly wider than shoulder-width apart, and lift it from the rack. Swing the bar slightly forward so that it's over your chest and has room to clear the rack.
3. Allow your elbows to flare out to the side as you bend your arms, lowering the bar toward your chest. The American Council on Exercise recommends stopping when your elbows are just below the level of the bench.

ExRx.net offers a series of interesting analyses of the bench press, including an option that using a wide grip offers a modest increase in pectoral activity. By comparison, doing a narrow-grip bench press greatly increases your triceps activity. So, if you want to focus on your chest as much as possible while doing bench presses, you should use a wide grip.

But a wide-grip bench press also places greater torque on your shoulders, as noted in a narrative review of powerlifting injuries, published in a July 2018 issue of the journal BMJ Open Sport & Exercise Medicine. In this review, researchers noted that, of the three exercises they studied (squat, bench press and deadlift), the most commonly reported injuries were from bench presses.

The good news is that you don't necessarily need to use an excessively wide grip — and invoke all that shoulder torque — to work your chest. This is confirmed by a small, independent study sponsored by the American Council on Exercise. In the study, researchers from the University of Wisconsin, La Crosse, tested EMG activity in 14 volunteers during a series of common chest exercises.

Of those exercises, the standard barbell bench press showed the most activation in the pectoral muscles. However, the difference between a wide grip and a normal grip on the bench press bar is only a couple of inches — about the width of your hand. If you're concerned about your shoulder stability, it's best to work with a trainer or medical professional (or both) to make sure you're using an appropriate grip and range of motion.

Sometimes isolating your chest isn't so much working only your chest, but working the right part of it. Your pectoralis major is actually divided into two distinct parts: The sternal portion, sometimes referred to as the lower muscle fibers, and the clavicular portion or "upper" pecs.

Although both parts of your pectoralis major activate during a bench press, a small EMG study of 14 subjects, published in a 2016 issue of the European Journal of Sport Science, showed that involvement of the clavicular head of the pecs increases during incline bench presses (which place your head higher than your hips).

In the same study, declining the bench to -15 degrees (placing your head lower than your hips) or keeping it flat produced more activity in the sternal fibers of the pectoralis major — although it's interesting to note that muscle activation for both portions of the muscle varied throughout the range of motion, regardless of what incline or decline angle the subjects used.

Read more: How Many Pushups to Get Pecs?

The ACE-sponsored research on EMG activity during chest exercises makes a compelling case for incorporating bench presses into your chest workout. Even though they don't technically isolate your chest muscles, they still provoked the most chest activity of all the exercises tested. However, if you're looking to work out your chest, the bench press is not your only option.

In particular, two other exercises that do isolate the chest muscles, relatively speaking, showed almost the same levels of muscle activation. The pec deck exercise machine produced 98 percent of the chest activity generated by the bench press, and bent-forward cable crossovers produced 93 percent of the activity of the bench press.

Move 1: The Pec Deck

It's worth leaving the free-weight room to take advantage of a chest workout on the "pec deck," which might also be identified as a seated chest fly machine.

1. Sit down in the machine, placing your back against the back pad.
2. Plant your feet on the floor for stability and lift your arms to shoulder level, elbows bent at (or slightly less than) a 90-degree angle.
3. Place your forearms against the handles of the pec deck and press them together in front of you. Aim for a smooth, controlled motion.
4. Reverse the motion to complete the repetition, spreading your arms apart. This machine places your shoulders in a relatively vulnerable position, so limit yourself to a comfortable range of motion.

Move 2: Bent-Forward Cable Crossovers

This exercise requires a pair of high cable pulleys that face each other. Each pulley should be set up with a D-ring handle.

1. Grasp the handle of one pulley and walk it across to the other pulley so you can grab that handle, too.
2. Position yourself between the pulleys and take a step forward with one foot to give yourself a more stable stance. Use your core to stabilize your torso as you hinge slightly forward from the hips. This is your start position.
3. Bring your arms down and in so that your hands overlap each other in front of your hips. Your elbows should stay slightly bent throughout the motion, and your palms should face inward and slightly down.
4. Slowly spread your arms back to the starting position.

Although the other exercises in the ACE-sponsored research didn't rank as high in terms of chest muscle activity as the bench press, pec deck and bent-forward cable crossover, they can still be a useful part of a whole-body strength-training program. Those alternate exercises, which produce between 61 to 79 percent of the chest activity of the bench press, are:

• The chest press machine
• Inclined dumbbell flyes
• Dips
• Suspended push-ups
• Stability ball push-ups
• Standard push-ups

With that said, a June 2017 article in the Journal of Exercise Science & Fitness offers an interesting look at the results of low-load bench pressing versus push-ups. Although the study pool was small — just 18 participants, all of them male and between ages 19 and 22 years — it's worth noting that the participants who did push-ups received similar gains in muscle size and strength as those who did low-load bench presses to failure.

These two studies didn't measure exactly the same thing. The former gauged activity in only one muscle, while the latter measured muscle thickness in three different places and used several different tests to gauge strength. However, they both confirm a very important point: Some activity is better than none.

So, unless you're bodybuilding or training for a sport or movement that requires a very specific range of motion through the chest, the best exercise for working your chest is going to be the one you're willing to do consistently, two to three times per week.

Read more: Stretches for the Pectoral Muscles

Speaking of strength-training several times a week: There's a tendency to focus on the chest muscles when weightlifting, especially for men, because they're impressive and easy to see when you're looking in the mirror. But for optimal health, the U.S. Department of Health and Human Services recommends training all your major muscle groups twice a week.

That means working not only your chest but also your back, glutes, hamstrings, quads, shoulders, arms, calves and core. And although the benefits of that full-body training might not be quite as immediately obvious as a good chest pump in the mirror, they are many.

Just a few examples include burning more calories, strengthening your bones, improving your physical stamina, bettering your cognitive function and managing chronic conditions such as back pain, heart disease, depression and diabetes.