7 underarm exercises that strengthen often-forgotten arm muscles

Even if you have what feels like a well-rounded fitness routine, with a glutes and lower body workout here, an arm workout there, and some core sprinkled in, there’s a high likelihood that there are still some muscles that fall by the wayside. One of the most ignored areas of the body? Your underarms. When you incorporate underarm exercises, you’ll reap benefits in your overall strength.

Within your underarm area are a number of muscles that are important for total upper body strength. According to Nathan Mago, athletics director for F45, it’s important to look at the whole surrounding area: the arms (biceps, triceps, and deltoids), the chest (pectorals), and the upper back (latissimus dorsi, rhomboids, and trapezius). “It’s key to work all of these in balance to help improve both your posture and upper body strength,” he says. Keep scrolling to learn about the numerous benefits your body will reap from doing underarm work, plus how to incorporate the proper exercises into your workout routine.

The benefits of working your underarm muscles

Having strong underarm muscles basically equates to stronger upper body strength. “When you’re engaging this area, the back of the shoulders, and the wrapping around the upper ribs, it’ll help to make underarm exercises more effective not just for strength but for optimal mobility for our body,” says fitness instructor and core specialist Erica Ziel. “Strengthening your tricep muscles, for instance, play a role in posture and overall balance of strength for your arms as well as your shoulders and mid-back. And the mid-back muscles play a part in underarm exercises because you can’t properly strengthen the back of your arms without being able to connect with the mid-back.” She adds that, generally, learning how to activate certain muscles within the underarm region can improve your performance in all of your upper body workouts.

Also, your upper body—which includes your underarm muscles—is responsible for keeping you upright. Mago points to tech neck as a common issue thanks to desk and couch life, but says that underarm exercises can help to combat it. “Underarm-focused workouts improve your posture, and decrease the aches and pains in the area—and I find them especially important in helping to get rid of neck pain,” says Ziel.

Before you incorporate these into your workouts, Mago recommends to take your time in getting your technique right before adding speed or heavier weights into your movements. “Sometimes it takes a few sets of a movement to develop that neuromuscular connection and to understand what it should feel like,” he says. “When in doubt, reach out to a trainer for guidance.”

7 underarm exercises to try

1. Reverse plank

Ziel likes this plank variation for strengthening the triceps, mid-back muscles, and the back of your legs (and of course your abs since it’s a, ya know, plank). If you need to modify, you can sit on the edge of a chair or bench instead of on a mat.

Sitting up tall, place your hands slightly behind you, engage your mid-back and triceps muscles, and lengthen your legs out in front of your body. Exhale as you do a pelvic tilt, engaging your abdominals, and slowly lift your hips off of the ground. You should feel the backs of your legs working as well as your mid-back and triceps. Inhale to hold, then exhale as you slowly lower your body, keeping your torso tall and lifted. Repeat for three to five reps.

2. Tricep kickback

When you first do this exercise, Ziel suggests beginning with light dumbbells (think around three pounds). “Make sure you are connecting properly with your mid-back and the backs of your shoulders in order to best strengthen the triceps,” she says. Once you nail it, you can start to gradually increase the weights that you use.

In a hinged-forward position, lengthen your spine, engage your mid-back and shoulders, and bring your elbows to your side. Exhale as you extend your arms straight back, keeping your elbows by your side. Inhale as you bend your arms back to starting position, keeping your elbows by your side. Repeat for 10 to 20 reps.

3. Standing straight-arm pulldown

Doing these at home, you can use a resistance band, according to Ziel, who likes the exercise for strengthening the lats.

Standing tall about a foot more than arms’ length away from your exercise band, grab the band with straight arms and lightly engage your core and mid-back as you open up across your chest. Exhale as you pull the band down, only going as far as you can while keeping your spine tall—avoid rounding your shoulders. Inhale as you control the return of the band to starting position and avoid releasing your underarm and mid-back connection. Repeat for 10 to 20 reps.

4. Standing tricep pulldown

These are similar to the straight-arm pulldowns, but instead focus on your tricep muscles. A resistance band will work for this one as well.

Standing tall about a foot more than arms’ length away from your band, grab the band and bring your elbows to your sides—not behind. Engage your core and mid-back as you open up across your chest. Exhale as you extend your arms straight while pressing down towards the floor. Avoid rounding your spine forward and keep your back lengthened, then inhale to bend your arms back to the starting position. Repeat for 10 to 20 reps.

5. Pilates side twist

For a Pilates-style exercise that works your underarm muscles and your core (including your obliques), Ziel recommends working through the side twist. Modify by placing your hand on a chair or bench to take stress off of your neck if it feels to hard with your hand on the ground.

Sitting with your hips on your mat and right hand pressing down, create opposition through your arm by pressing your hand into the mat and exhaling to feel a pulling up of the arm muscles into the shoulder and the side of your ribs. Inhale as you use your legs and arm, shoulder, and mid-back to press your body into a side plank. Exhale as you twist, piking your hips up towards the sky and pulling your torso away from your wrist. Twist as you reach your left hand around the front of your body to the right. Inhale to return to the side plank. Repeat for three to five reps then do the same on your other side.

6. Wide grip row

Mago likes this row variation for hitting the upper back muscles, and it’s one that you can do with a suspension trainer (like a TRX) or a resistance band. If you’re using a resistance band, wrap it around something at chest height.

With your palms facing downwards, keep your chest, hips, and knees in one line as you pull yourself upwards. Squeeze through the shoulder blades and bring your hands to the outside of your chest, then return to starting position with control. Try to do four sets of 15 reps.

7. Diamond push-up

For a challenging twist on the classic push-up, Mago suggests trying this one to target your chest, shoulders, and arms. “It’s a sure-fire way to light up all of those muscle groups,” he says.

Start in a push-up position, but with your hands on the floor in line with the middle of your chest in a diamond shape. Lower with control to the floor, then push through the hands as you keep the feet, knees, hips, and shoulders all in one straight line. Keep your core engaged the entire time. Do four sets of 10 to 15 reps, and drop down to your knees if you need to modify.