One Arm Dumbbell Z-Press Exercise Form Guide with Video & Pictures
One Arm Dumbbell Z-Press

One Arm Dumbbell Z-Press Exercise Form Guide with Video & Pictures

Exercise Name

One Arm DB Z-Press

Also Called

Single Arm Z-Press, Unilateral Z-Press

Primary Muscles

Secondary Muscles

Function

Strength

Mechanics

Compound, Unilateral

Force

Push

Required Equipment

Optional Equipment

Wrist Wraps, Lifting Belt, Chalk

Experience

Beginner

Rep Range

6-15

0-0-x-1

Variations

Bench-Seated One Arm DB Z-Press, One Arm Kettlebell Z-Press, Bilateral DB Z-Press

Alternatives

Barbell Z-Press, Overhead Press, Shoulder Press, Bottoms-up Kettlebell Press, Bradford Press

One Arm Dumbbell Z-Press Instructions with Pictures

1. Starting Position

  • Sit on the floor with the legs outstretched in front of you, knees extended, and the hamstrings laying flat against the ground.
  • Actively brace the abdomen and achieve a slight posterior pelvic tilt in order to keep the lumbar spine in a neutral lordotic posture.
  • Use both hands to set the dumbbell in position over the working shoulder.
One Arm Dumbbell Z-Press Setup

Be sure to grasp the bar with both hands to bring it up to your shoulder. Even if you're capable of doing it with one hand, it's smarter and safer to do use both. Source for this image and images below: SupremeStrengthTV

  • Remove the off hand from the dumbbell and use it as a counter balance for the loaded side.
  • Establish control and stability of the weight by actively keeping the elbow tucked in the both shoulder blades retracted and depressed.
One Arm Dumbbell Z-Press Starting Point

This is the your starting position. Remember to keep your core braced, paying particular attention to your obliques; actively contract them such that your torso remains facing the front and resist the tendency rotate excessively to one side. Also, you can spread your legs wider than shown if needed for better balance/stability.

2. Concentric Movement

  • Once the dumbbell is motionless and you have complete control over the weight, press the weight overhead with a slight flare of the elbow.
  • Focus on both your abdominal bracing, slight pelvic tilt, and your shoulder blade position (retracted) during the press.
  • Forcefully squeeze the dumbbell handle.
  • Raise the arm overhead until the elbow is locked.
One Arm Dumbbell Z-Press Concentric - Side View

Fully extend the elbow to complete the rep. Remember, keep everything tight in the core region. Also, focus on activating the right scapular muscles in concert with your delt, to keep your shoulder joint stable and achieve proper scapulohumeral rhythm.

One Arm Dumbbell Z-Press Concentric - Front View

Use your free hand as a counterbalance. Kind of like how a cat uses its tail to balance itself. But do NOT anchor your hand to the floor at any point. That is cheating! Keep it elevated.

3. Midpoint

  • Once the elbow has completely extended, ensure the shoulder blades remain retracted in order to keep the shoulder from being pressed out of position. 
  • Hold the midpoint position until all motion of the dumbbell has ceased

4. Eccentric Movement

  • Lower the dumbbell with a slight tuck of the elbow. 
  • When the weight has returned to the start position, regain any lost core bracing and postural rigidity.
One Arm Dumbbell Z-Press Eccentric - Side View

Note how the dumbbell goes down all the way until it touches the top of the shoulder. With lighter weight, I don't really recommend letting it rest there at all. However, when you get up to heavier weight, you may inevitably need to let the dumbbell sit hear, to briefly recoup between reps. This is okay, as long as you're not staying there for much more than a second or so.

One Arm Dumbbell Z-Press Eccentric - Front View

Note the tucked elbow position. As shown, it is at about a 30 degree angle relative to the torso. You can go as far as 45 degrees. But don't flare it any further than that, as it's potentially dangerous to your shoulder joint.

5. Repeat

  • Do not “bounce”into the next rep. Let the weight settle and deliberately press into the next rep.

Common One Arm Dumbbell Z-Press Errors to Avoid

Mistake:

Solution:

​Lateral Trunk Flexion

If midline stabilization fails and you start tilting your torso one way or the other, either refocus on your core tension or lower the resistance until you find a weight that doesn’t compromise your posture.

Dumbbell “Swaying” at Lockout

During the press, ensure the shoulder blades are forcefully retracted together. This will make the joint more stable by setting the humerus further back/deeper into the shoulder capsule.

​Losing Lumbar Rigidity

If constantly and actively tucking the hips and bracing the abdomen is still resulting in the lower back going into flexion, then the issue may be with your lower body. Try slightly bending the knees. This will put some slack into the hamstrings and allow more hip ROM. If this fixes the problem, you might want to invest some time into working on hip/hamstring mobility.

​Thoracic Hyperextension

If you’re extending your upper back to the point that you’re pressing the dumbbell out in front of you and leaning back underneath it, focus on slightly tilting the hips forward and pulling the sternum “down towards your belly button.” This will help return the thoracic spine to a neural position and assist in keeping an active brace in the abdomen as well.

One Arm Dumbbell Z-Press Tips

  1. The concentric movement should be very fast and very explosive. Focus on applying as much force as you possibly can while still maintaining good postural control.
  2. Slightly keep a posterior pelvic tilt and an actively braced abdomen in order to keep the lumbar spine in a neutral alignment.
  3. Slightly flare the elbow on the press, slightly tuck the elbow on the eccentric.
  4. Keep both shoulder blades tightly retracted together and don’t “press out of your shoulder” and lose tension at the completion of the lift.
  5. Focus on keeping your wrist straight throughout the motion. Don't let it bend back all the way.
  6. Start with your weaker side first. Then, on your stronger side, only do as many reps as you did on your weak side (even if you're capable of doing more on your strong side).
  7. Spread your legs further apart on the floor if you need more balance/stability. However, don't spread your legs further apart than needed.

Is the One Arm Dumbbell Z-Press Right for You?

This exercise is exclusively for those lifters with excellent postural control. If losing midline stability and alignment is a problem for you on other lifts, it will be and issue here as well. Once that variable has been properly trained and improved, pretty much every lifter can benefit from the one arm dumbbell Z-press...

...At the same time, this lift may be helpful for fixing this stability/alignment issue if you have it. The only caveat being that you should go light and progress slowly! That, along with actively improving midline stability and alignment on all other lifts where it's an issue, will help you fix it faster.

The shoulder is a common injury site for serious lifters. Unilateral training geared towards improving the synergistic surrounding musculature of a joint (especially an inherently unstable joint like the shoulder) will definitely pay dividends later on in terms of health and training longevity.

About the Author Alex

Hey! My name is Alex, and I'm the owner and author of King of the Gym. I started this website back in late 2009 during college, and it has been my pet project ever since. My goal is to help you learn proper weight training and nutrition principles so that you can get strong and build the physique of your dreams!

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