1 1 2 Hammer Curls: How To, How Not To, and Benefits

The 1 1 2 hammer curl is a variation of the traditional hammer curl which simply enables an extended set of the movement to be performed. It is often used with a dumbbell, however, a cable machine could also be used because the arms must work independently in order to complete the 1 1 2 rep pattern.

One entire “rep” is composed of each arm performing a hammer curl followed by both arms doing a simultaneous hammer curl. A 1 1 2 hammer curl would look like this:

Phases of the 1 1 2 hammer curl
  • Left arm do a hammer curl, right arm hangs.
  • Right arm do a hammer curl, left arm hangs.
  • Both arms hammer curl with a squeeze at the top.
  • Repeat.

We’ll cover the ways to “repeat” below in our How to section.

As you can see, the 1 1 2 hammer curl is more a rep structure than it is a modification of basic hammer curl form.

Muscles Worked by 1 1 2 Hammer Curls

1 1 2 hammer curls work the biceps brachii–both short and long heads, the brachialis, and the brachioradialis dynamically, and the forearm muscles are intensely worked isometrically due to the extended length of a set of 1 1 2s.

Biceps, brachioradialis, and brachialis muscles

The aim of the 1 1 2 hammer curl is muscle fatigue and sets done to volitional failure as a means of overload, which in turn is intended to spur muscle growth.

Volitional failure is the inability to perform another rep at all, whereas “technical failure” is the inability to perform another rep correctly. You should never perform exercises to technical failure as injury can occur in that zone.

So, because 1 1 2 hammer curls work to volitional failure, the smaller muscles are going to fatigue first assuming all other things are equal.

Assuming that’s true, you can expect 1 1 2 hammer curls to intensely work the muscles of the forearms and the brachio-radialis. 

Again, the forearms are being loaded isometrically, which is not as renowned for building mass as dynamic loading, which the brachio-radialis experiences.

How to Do 1 1 2 Hammer Curls Properly

Steps of the 1 1 2 hammer curl

Proper form is always important and when an exercise is designed for the express purpose of generating fatigue, attention to proper form becomes especially important.

Here’s how to do a set of 1 1 2 hammer curls properly:

  1. Select a weight you can curl with strict form for the desired number of reps.
    • Dumbbells are the traditional instrument of choice but a two-axis cable machine will work well for 1 1 2 hammer curls as well.
    • If using a cable machine, the pulleys must be no farther than shoulder-width apart. If you don’t have one of these handy, you’ll need to resort back to dumbbells.
    • Cables have the advantage of keeping tension on the muscle longer than free weights can. The cable is always “pulling” where dumbbells are at rest when arms are at the sides.
  2. Get a neutral thumbs-up grip. At rest, the thumbs should be facing forward, palms toward the body.
  3. Bending only at the elbow, curl with one arm. Lower the weight. (That’s “1”, 1/3rd of a rep.)
  4. When the first arm reaches bottom, start curling with the opposite side arm. Lower that weight. (That’s the 2nd “1”, 2/3rds of a rep.)
  5. Now, curl both arms simultaneously, and pause with a strong flex (aka squeeze) at the top. (And that’s “2” and one complete 1 1 2 “rep”.)
  6. Repeat that pattern, keeping in mind that if you start the following rep with the same side you did before, that side will receive less rest between each 1 1 2 hammer curl rep. So here’s a suggestion:
    • Start with right-left-both.
    • Then, left-right-both.
    • Repeat.
    • This pattern keeps the fatigue evened out over the course of two 1 1 2 hammer curl reps.
How to properly do 1 1 2 hammer curls

How NOT to Do 1 1 2 Hammer Curls

The 1 1 2 hammer curl is subject to the same mistakes common to other hammer curl variations and will be subject to fatigue-related errors simply due to the exercise’s design.

Cheating as your arms tire

Cheating takes several forms like letting your grip fail. Here are two types of hammer curl grip failure:

Turning palms up

Wrong grip for hammer curl - palms up

Palms-up grips turn a hammer curl into something else. It might be a good biceps exercise, but it wouldn’t be a hammer curl. We need to maintain discipline in terminology if we hope to communicate exercise education and programming.

Adducting the wrist

Wrong grip for hammer curl - adducted wrist

Letting your thumb side fall forward and down is adducting the wrist. The movement should resemble its namesake, hammering.

You should be able to set a ruler flat along the back side of your forearm up to your knuckles with no gaps. The thumb should stay “high”.

If you couldn’t throw a punch with the same grip you use for hammer curls, you don’t have a proper hammer curl grip.

Moving the elbow

Showing proper elbow positioning for hammer curl

The one and only thing that should be moving is the forearm. The elbow should remain tucked in at the sides at the same position throughout the entire movement and act simply as a hinge.

If the forearms are moving forward or backward at any point, the curl becomes easier because your whole arm, not just your forearm, is doing the work. That means there will be lesser pain and therefore lesser gain.

If the only way those dumbbells are going the be curled up successfully is by moving the elbow, then you’re going too heavy – drop down in weight until proper elbow positioning can be achieved for the full range of motion.

Not fully extending the arm

Related to the point above, the target muscles must lower the weight all the way to the bottom of the range where the weight is at the side.

Keeping arms bent while bending forward and backward at the waist is not a curl of any sort. Yet we see this all the time in the gym among novice lifters.

If your objective is to build your arms, you’ve got to actually move the arms.

Doing a funky Good Morning variation in the name of hammer curls won’t do a thing for your arms, or your reputation in the gym.

Swinging the weights

Swinging the weights

Winding up to initiate the curl turns this exercise into “cheat curls”. There’s a place for cheat curls (at least, I’ve heard there was). To get the arm-building benefits of the 1 1 2 hammer curl, you’re better off using only your biceps and companion anterior upper arm muscles only.

Benefits of 1 1 2 Hammer Curls

Provides great conditioning

The 1 1 2 hammer curl’s chief benefit is that it “tricks” the lifter into doing a very high rep set without it seeming like a high rep set. An 8-rep set of 1 1 2 hammer curls is actually 24 reps (3 individual hammer curls per 1 1 2 “rep”.)

Before you know it, you’ve done a lot of arm work. If you maintain good form through the entire set, you can get a really good workout in a relatively short period of time.

Promotes Type IA muscle fiber development.

The biceps are roughly 60% Type IIA (fast twitch) muscle fiber, meaning that about half are the slower twitch Type IA fibers known for endurance. That’s over-simplified but directionally-correct.

Longer sets that create a lactic acid burn like 1 1 2 hammer curls do will be better suited to building Type IA fibers.

Programming for physique should balance exercises and set-rep combinations that work both Types I and II muscle.

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Perry Mykleby, ACE CPT

Perry started lifting weights in 1974. He is an ACE-certified personal trainer and fitness writer. He holds a journalism degree from the University of North Texas, where he competed in powerlifting. His final competition was the Texas State Open in December of 1982, but has continued to study and practice muscle strength and hypertrophy. He is a four-decade veteran of the medical device industry.

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