Everything You Need to Know About Hammer Curls

Hammer Curls

Getty/Design by Cristina Cianci

After a year of working out from home, your stray dumbbells have probably become your best friends. And mastering some basic strength training exercises is the key to making the most of your home gym. Enter hammer curls: A twist on the classic bicep exercise.

But what are hammer curls, and how do you do them? To help you slay this exercise, trainers explain everything you need to know about hammer curls and whether or not you should make them a part of your fitness routine.

Meet the Expert

What Is a Hammer Curl?

Hammer curls are a variation of a standard bicep curl where your palms point towards each other instead of facing upwards, says Joe Allen, a New York City-based Barry's instructor. You do hammer curls much the same way you do a standard bicep curl. Start by picking your dumbbells of choice. Then lift the weights to your shoulders and lower them back down to your sides with control. If that seems almost identical to a standard bicep curl, it's because it is — nonetheless, simply facing your palms in a different direction can work extra muscles and challenge your mobility in new ways, adds Emma Middlebrook, a certified personal trainer, and owner of REP Movement.

Benefits of Hammer Curls

According to Allen, hammer curls work your bicep muscles and then some, which makes them the perfect exercise for when you're sick of doing regular curls or want to focus on multiple muscles at once.

  • Arm strength: Like a standard curl, this exercise targets your biceps (also known as your biceps brachii muscle). And rotating your hands to face each other throughout the movement also engages your forearm muscles (called the brachialis and brachioradialis), says Middlebrook. The result? A full arm workout in one simple move.
  • Grip strength: There are benefits beyond just strengthening your arm muscles, Middlebrook tells Byrdie. Hammer curls challenge your wrist strength and grip, which can prep you for heavier lifts in your weight training regimen, like deadlifts.
  • Improve mobility: And hammer curls are a functional exercise, which means they mimic natural movement patterns — in this case, a pulling motion — to help make everyday movements easier and more accessible, like carrying a heavy box or picking up your kids.

Proper Hammer Curl Form

If you're ready to hit the hammer curls, follow the trainers' tips to slay your reps with perfect form.

  • Stand or kneel with your legs about hips-width distance apart.
  • Face your palms in towards your body.
  • Squeeze your biceps to lift your weights to your shoulders. Keep your shoulders down and back.
  • Slowly lower your weights back down to your sides.
  • Repeat for two or three sets of 10 to 12 reps.

Common Hammer Curl Mistakes

Hammer curls are a simple but effective exercise that anyone can safely try. Just remember to focus on your form and take it slow to engage your muscles throughout the movement, says Middlebrook. Relying on momentum, letting your elbows hike out to the sides, and shrugging your shoulders can compromise your form and potentially lead to injury, so prioritize technique as you build hammer curls into your strength training regimen.

The Best Hammer Curl Modifications

If you're looking for options, there are a few ways to modify hammer curls to suit your fitness level or preferences better. If you feel your form slipping or are having a hard time getting through all your reps, then Allen recommends opting for lighter weights at first. You can work your way up to heavier dumbbells from there as you build strength and master form. He also suggests doing hammer curls alternating one arm at a time instead of moving both at once to avoid overdoing it.

And if you're not feeling dumbbells, no problem! You can also do hammer curls using resistance bands or cable machines to reap all the benefits of the exercise using your equipment of choice, says Middlebrook.

The Takeaway

Hammer curls are a staple resistance training exercise that works your bicep and forearm muscles to help you build strength and mobility to benefit you in the gym and beyond. And besides boosting your strength, this exercise can also help you master grip and form to carry into other strength training moves. Try it with weights, bands, or cables, or opt for doing the exercise one arm at a time — whatever your ideal hammer curl looks like, this exercise is sure to be a go-to drill come arm day.

Related Stories