The Benefits of the Concentration Curl
Concentration curls are among the most popular arm isolation exercises, with roots dating back to the 1960s. Back then, every bodybuilder did the exercise to pump their biceps and boost their chances of winning competitions. For instance, Arnold did concentration curls by bending forward and having his working arm hang straight down. Then, from that position, he would curl the dumbbell as many times as possible, ensuring his elbow remained steady.
Concentration curls aren’t as popular these days, thanks to cable machines, curl machines, and preacher benches taking over arms training. Still, the exercise is beneficial and can lead to impressive bicep growth when used correctly. Plus, all you need is a dumbbell and somewhere to sit.
Doing concentration curls is relatively simple, but there are some nuances you should learn. The objective is to sit down, bring your working arm between your legs, and place the tricep against the inner thigh. Then, curl the dumbbell, switch arms, and perform the same number of repetitions. Unfortunately, that guidance alone isn’t always enough for trainees to take full advantage of the exercise, so we’ll discuss it more in-depth below.
We recommend including the concentration curl late into your ‘pull’ or bicep sessions. Start with a light dumbbell to get familiar with the exercise, and do at least 15 slow and controlled repetitions per side.
Level of Exercise: Beginner
How to do a Concentration Curl
- Take a lightweight and sit on a flat gym bench.
- Spread your legs wide and place the dumbbell on the floor between your legs.
- Reach down and grab the weight with your right hand.
- Lift the weight off the floor and place the right tricep (upper arm) against your inner leg.
- Keep your chest out and body stable, take a breath, and straighten your arm.
- Curl the dumbbell slowly until your wrist is higher than your elbow. As the dumbbell moves up, keep your upper arm in the same position against your inner leg and avoid having it move up.
- Pause for a moment and squeeze your muscle at the top of the repetition. Your palm should face the ceiling.
- Lower the dumbbell slowly and extend your elbow entirely as you exhale. Feel the muscle work throughout all reps.
- Take another breath and repeat.
- Once finished, set the weight on the floor, reach with your opposite hand, and grab it.
- Set yourself up the same way, having your left tricep (upper arm) against your inner leg and your body stable.
- Repeat for the same number of reps, performing each slowly, and squeeze your upper arm at the top of each rep.
What muscles does a concentration curl activate?
Concentration curls are an isolation exercise that strengthens and develops the bicep (1). The muscle group covers the front of our upper arms, and its primary function is to produce elbow flexion (bending the arms) (2). Our biceps also play a role in wrist supination, which occurs as we rotate our palms from a neutral to a forward-facing position.
Similarly, concentration curls engage the brachialis muscle group, which lies underneath the bicep and assists with elbow flexion (3). Developing the brachialis pushes the bicep out more, making our upper arms appear larger and more muscular.
Our brachioradialis also contributes during concentration curls but to a much smaller extent. The muscle covers the top of our forearms and contributes to elbow flexion (4).
Concentration Curl Vs. Bicep Curl
Concentration curls and regular curls are identical in many ways. Both exercises isolate the biceps, causing them to grow and get stronger. The two activities also offer the same range of motion, which means they activate the muscle similarly.
The primary difference between concentration and regular curls is that you must perform the former with a dumbbell or kettlebell, whereas regular curls offer more variety. You can do regular curls with dumbbells, kettlebells, EZ bars, barbells, cable machines, etc.
Another difference between the two exercises is that regular curls allow you to train seated or standing, whereas you typically perform concentration curls seated. You can perform Arnold’s version where you bend from a standing position, but that could make it more difficult to isolate your bicep because your thighs don’t keep your elbows stationary. Plus, folks with lower back issues might find that version of the concentration curl uncomfortable.
Research notes another significant difference between concentration curls and most other bicep exercises. In an ACE-sponsored study from 2014, researchers compared eight of the most common bicep exercises (1). The objective was to determine which exercise caused the most significant biceps activation. Sixteen men and women with some lifting experience performed all the exercises while having electrodes hooked on their anterior deltoids, biceps, and brachioradialis muscles. Concentration curls showed the highest bicep activation, with cable curls coming far behind at the second spot.
Researchers noted that a likely explanation for the effect is that concentration curls force the muscle to do all the work. In contrast, the shoulders and brachioradialis can take away some of the weight during most other curls, resulting in lesser muscle activation. A notable benefit of concentration curls is that you can easily take your ego out of the equation and train your bicep well, even when using a lighter weight.
Variations and Modifications of the Concentration Curl
1. Standing Concentration Curl
One way to perform the exercise is as Arnold did concentration curls back in the day. Grab a dumbbell, bend, and let your arm hang straight down. Once in position, curl the dumbbell while keeping your elbow and body steady. Alternatively, you can lean, stagger your stance, and place your elbow against the inner leg, similar to how you would during seated concentration curls. Once finished training one side, set the weight on the floor, pick it up with the opposite hand, and do the same number of reps.
2. Hammer Concentration Curl
Hammer concentration curls are a movement that allows you to use slightly more weight and involve your forearm muscles better. Instead of keeping your palm neutral, you must rotate it so your thumb points at the opposite thigh instead of forward. Perform reps slowly and squeeze your muscles throughout from start to finish.
3. Bodyweight Concentration Curl
Bodyweight concentration curls are among the weirder exercises you can do for your bicep, but the movement works if you don’t have any equipment. The objective is to sit and assume the same position as you would for traditional concentration curls. But, instead of grabbing a dumbbell, place your hand underneath the opposite thigh and lift it repeatedly. You can increase the difficulty by pushing the thigh down to create extra resistance for the working muscle.
4. Cable Concentration Curl
Performing the concentration curl on a cable machine is beneficial for keeping constant tension on the bicep. You can do the cable movement by attaching a handle to a low pulley, grabbing it, and standing sideways. Bend your body, position your elbow against your inner leg, and do slow reps. Once finished, rotate 180 degrees and train your other arm.
Mistakes to Avoid
Elbow Traveling Up
A common error with concentration curls is allowing the elbow to travel up the inner thigh as you lift the weight. People are often unaware of the mistake but doing so makes each repetition much easier and less effective. Having your elbow travel up means it can end up over your thigh, taking away the tension from your bicep. Avoid the mistake by anchoring your elbow against the lower inner thigh and keeping it there from start to finish. An excellent way to ensure a stable elbow position is to keep your torso steady and avoid lifting it as you curl the weight.
Shortening The Range of Motion
The second common error with concentration curls is shortening the range of motion, which trainees do to compensate for using a heavier weight. Unfortunately, a shorter range of motion offers no real benefits because it prevents you from effectively contracting and stretching the bicep, making the exercise less effective. Avoid the error by using a lighter dumbbell and training with a full range of motion. Lift the weight until your wrist is higher than your elbow, and lower it until your arm is completely straight and you feel a stretch in the biceps.
Similar to the previous error, trainees often resort to momentum to compensate for using too much weight. The problem with momentum is that it takes the tension away from your bicep, which leads to poor results. Fix the mistake by using a lighter weight you can control with smooth technique and do slow reps without using jerking motions.
Similar Exercises to the Concentration Curl
Bicep Curls (Dumbbell)
Dumbbell curls are a simple and effective exercise for the biceps, brachialis, and brachioradialis (5). Like concentration curls, you’re using dumbbells for weight and are training through the same range of motion. The primary difference is that you’re more likely to cheat by using momentum and swinging your body during traditional curls because you’re upright and your elbows are unsupported.
Hammer Curl (Band)
Similar to the concentration curl, banded hammer curls are beneficial for improving your technique and activating your biceps more effectively. The exercise is beneficial because bands provide linear variable resistance (LVR). Lengthening a band results in more resistance for your biceps, making it nearly impossible to use momentum. Instead, your biceps must remain active from start to finish, resulting in more effective sets promoting growth.
Bicep Curl (Machine)
Machine curls are another fantastic exercise for isolating and developing the biceps. Similar to concentration curls, you perform the exercise from a seated position. The machine makes it difficult to use momentum or modify the exercise pattern, making it easier to train your biceps effectively. Some machines support your elbows, allowing you to isolate your biceps further, similar to the concentration curl.
Drag curls are a lesser-known exercise. Like regular curls, you must grab a straight bar and stand upright. But, instead of performing a standard curl, you must drag the bar against your body as you bend your elbows. Doing so is beneficial for preventing the use of momentum and activating your biceps more effectively.