How to Do a Triceps Extension: Proper Form, Variations, and Common Mistakes

Verywell / Ben Goldstein

Also Known As: Overhead triceps extension

Targets: Triceps (back of the upper arm), shoulders, core

Equipment Needed: Dumbbell

Level: Intermediate

The triceps extension is an isolation exercise that works the muscle on the back of the upper arm. This muscle, called the triceps, has three heads: the long head, the lateral head, and the medial head. The three heads work together to extend the forearm at the elbow joint. The triceps extension exercise is an isolation exercise because it involves movement in only one joint, the elbow joint.

How to Do a Triceps Extension

Verywell / Ben Goldstein

Begin standing with your feet in a slight split stance, with the left foot just slightly behind the right and the legs about hips distance apart. Weight should be evenly distributed between both feet. Soften the knees and be sure that the core is engaged so that you maintain good posture throughout the move.

You can perform this exercise with one dumbbell cupped in both hands, so the palms face the ceiling or with a dumbbell held in each hand. Alternatively, you can use a resistance band by standing on one end and holding the other ends in your hands behind your back.

  1. Lift the dumbbell directly overhead. Ensure the head stays aligned over the chest, the core remains engaged, and the shoulders are relaxed.
  2. Extend both arms fully, then exhale and slowly lower the weight, bringing the weight behind the head by bending at the elbows. Be sure the chest stays aligned over the hips and the back does not arch.
  3. Inhale and reverse the movement once you reach a 90-degree bend at the elbow or slightly further, lifting the weight back to the starting position. The weight should not touch the back of the head when it is in its lowest position.

Doing the triceps extension while standing challenges you to engage the core to stabilize the lower and mid-body while you move both arms simultaneously over your head.

Benefits of the Triceps Extension

Resistance exercises that work the triceps (back of the upper arm) and biceps (front of the upper arm) helps increase arm strength and build muscle in the arms. Many different exercises, such as the push-up or the chest press, work the triceps and other major muscles in the upper body.

But dedicating at least some time to targeting the triceps in isolation can help you to build strength in that area effectively because you won't be limited by weakness in other muscles.

A strong triceps muscle helps to stabilize the shoulder and elbow joints. Stable arm joints allow you to move comfortably through your day. Lifting heavy items over your head or pushing things (such as a door or moving furniture) requires strong triceps.

Strong triceps can help you to perform athletic activities like swimming, hitting a tennis ball, passing a ball in basketball, or throwing a ball in baseball. The triceps are also crucial for stabilizing the arm for fine motor activities like writing.

Other Variations of Triceps Extension

You can perform the triceps extension in several different positions. The most basic version is the standing triceps extension, but you can also complete the move in a seated position or lying on a weight bench or the floor (called a skull crusher). You can also choose to work one arm at a time or both arms together.

Increase or decrease the amount of weight you use to make the exercise more or less challenging. If you don't have a dumbbell, you can use a resistance band or lift household objects such as a water bottle or jug.

Seated Triceps Extension

start position seated triceps extension

Verywell / Ben Goldstein

The seated triceps extension is performed just like the standing variation, except you are seated on a chair, weight bench, or balance ball while flexing and extending a weight over your head.

Maintaining good posture in a seated position is more manageable because your hips are firmly grounded, and the lower body is at rest. But you still have to engage the core to keep the torso in alignment—you'll find that it is easier to stabilize the upper body.

You can perform this variation with one dumbbell, cupped in both hands, or a dumbbell held in each hand. Alternatively, hold a medicine ball or kettlebell in both hands.

Begin sitting on a ball or bench with your feet on the floor about shoulder-width apart. Be sure that the core is engaged so that you maintain proper posture throughout the move. The lift and extension of the weight is the same as in the standing version.

Lying Triceps Extension

start position skull crusher

Verywell / Ben Goldstein

This variation, called a skull crusher, is usually performed while lying on a weight bench. Technically, this is a different exercise than the triceps extension. Still, it is similar enough to be used as a modification if your upper body mobility limits your ability to perform the overhead version with good form.

You can perform this variation with one dumbbell, cupped in both hands, or a dumbbell held in each hand.

Begin by laying on a flat surface such as a weight bench or a mat on the floor.

  1. Hold the dumbbell with both hands, cupping it just like you would with the triceps extension, but hold it above your chest.
  2. Bend at the elbows to bring the weight down, so it starts to come behind your head. Keep the upper arms still and perpendicular to the body.
  3. Continue lowering the weight behind the head until the dumbbell head is at the same level as the weight bench.
  4. Reverse the movement until the weight returns to the starting position again.

Common Mistakes

Watch for these common errors when performing the triceps extension so you can perform the exercise safely and effectively.

Head Movement

Lifting and lowering a weight behind your head may feel awkward at first. If you don't have a lot of mobility in the upper back and shoulders, you may find that you move your head to accommodate the lifting and lowering process.

Try to keep the head and the body still and isolate the movement to the elbow joint. Keep the head aligned over the midline of the chest and the chest aligned over the hips. Keep your focus forward and chin off the chest. If you still find that you are moving your head, consider doing the exercise lying down.

Incomplete Range of Motion

If you haven't worked the triceps often, you may notice that they are weaker than some other muscles in the body. As a result, you might try to make the range of motion smaller than it should be. That is, you drop the weight just a few inches and then lift it back to the starting position. Often this is accompanied by an over-emphasis on the lifting phase and a quick but ineffective lowering phase.

Have a friend or a trainer watch you when you first try this move to make sure you achieve at least a 90-degree bend at the elbow when you lower the weight. Further is okay as long as you don't hit the back of your head. The lowering phase should be slow and controlled and the lifting phase should take just as long as the lowering phase. If reaching that 90-degree angle is too challenging, decrease the amount of weight that you are lifting.

Forward Elbow Placement

Probably the most common error when performing the triceps extension is letting the elbows float forward towards the front of the face. This is more common if your chest and shoulder muscles are tight. But it decreases the workload of the triceps and renders the exercise less effective. You want the arms directly overhead so that the biceps are close to the ears.

If you notice that your arms keep moving forward, try doing a few upper body stretches before doing the triceps extension. Doing the skull crusher variation might also help because gravity will help to pull the arms into position.

Flared Elbows

Another elbow issue occurs when the elbows flare out to the side. When the elbows move out away from the ears, it allows you to enlist the biceps and shoulders to assist the flexion and extension. The exercise will no longer isolate the triceps.

Be sure to keep the elbows tucked in to eliminate this problem. Reduce your weight as necessary to maintain the proper elbow placement.

Safety and Precautions

If you are new to exercise or a strength training routine, check with a healthcare provider to make sure that there are no special modifications that you should follow. If you have been sedentary or are returning to exercise after pregnancy or an injury, get clearance from your doctor first.

In the triceps extension, because you are lifting a dumbbell over your head, you should be careful not to lift more weight than you can safely control. Dropping it could cause harm. If you are challenging yourself with a new weight increment and are unsure of your ability to handle it, have someone spot you.

Complete two to three sets of 10 to 12 repetitions each. Try to remember to change the leg in front and the hand on top holding the weight.

Frequently Asked Questions

  • Are triceps extension effective?

    Triceps extensions are very effective for isolating the triceps muscles. There are several variations but the overhead triceps extension has been shown to increase muscle mass the most.

  • What is the best tricep exercise?

    The best triceps exercise is the one that works the best for your anatomy and trying several exercises over time is best. However, some research points to the triangle push-up being a superior exercise for activating triceps heads. Other excellent exercises are the close grip bench press, triceps kickbacks, and triceps dips.

  • Are tricep extensions the same as skull crushers?

    Triceps extensions are not quite the same as skull crushers, although they are similar, the names help differentiate the position you start in. Skull crushers involve laying on your back and moving the weight behind your head while keeping the elbows above you and relatively stationary. Triceps extensions are typically performed standing with the weight held above your head.

Try It Out

Incorporate this move and similar ones into one of these popular workouts:

4 Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Maeo S, Wu Y, Huang M, et al. Triceps brachii hypertrophy is substantially greater after elbow extension training performed in the overhead versus neutral arm position. European Journal of Sport Science. Published online July 12, 2022:1-26 doi:10.1080/17461391.2022.2100279

  2. Landin D, Thompson M, Jackson M. Functions of the triceps brachii in humans: A review. J Clin Med Res. 2018;10(4):290-293. doi:10.14740/jocmr3340w

  3. Tiwana MS, Bordoni B. Anatomy, shoulder and upper limb, triceps muscle. In: StatPearls [Internet]. StatPearls Publishing.

  4. American Council on Exercise. ACE Study Identifies Best Triceps Exercises.

By Malia Frey
 Malia Frey is a weight loss expert, certified health coach, weight management specialist, personal trainer​, and fitness nutrition specialist.