How to Do Barbell Curls (Form & Muscles Worked)

When the topic of working out and getting jacked comes up, the first thing to be flexed is always  the bicep.

Not only is it one of the most noticeable of the vanity muscles, but it can also be one of the most impressive.

A set of sleeve-filling arms look good on any guy and signals to everyone around that a lot of hard work has been put in the gym. But how does one get these sleeve-filling biceps?

Barbell curls are the classic choice, and for good reason.

They’re relatively simple to perform and have been tried and tested for decades. When done correctly, they can ramp up your gun show to the next level—but the key is to do them correctly.

Muscles Worked with Barbell Curls

Barbell curls are an isolation exercise, meaning that they primarily isolate the biceps brachii. This is different from compound movements such as squats, deadlifts, and the bench press which use many different muscle groups across your entire body. However, it’s a little more complicated than that.

Curls will hit both the short head and the long head of the biceps, with about an even emphasis on each. Since curls rely on elbow flexion and forearm supination, you can expect a well-rounded bicep workout.

Barbell curls also engage the forearm muscles to a high degree. The brachioradialis and brachialis muscles are both also active during elbow flexion, and so they play an important role in curls.

Although the forearms aren’t a primary player in this lift, they do a lot to support the biceps during the movement. Not only will your biceps get bigger with barbell curls, but you should also see a marked difference in forearm size and the strength of your grip.

The Benefits of Barbell Curls

The biggest reason barbel curls should be a part of your routine is the increase in upper-body mass. Compared to other curling exercises, the barbell curl is unique in that you’ll be able to load more weight onto your muscles than many other curl variations. The greater a load you place on your muscles, the more muscular development you can expect. While the lift mainly isolates your biceps and forearms, even your chest, shoulders, and traps will come into play slightly.

Strength Carryover

Although the biceps are a smaller muscle, the gains you see there will carry over to other, larger lifts. For example, things like chin-ups (and even pull-ups), lat pulldowns, and rows will become easier since they rely so much on your elbow flexors.

If you’re looking to improve your back workouts and pulling exercises, your biceps may be the thing that’s holding you back. Stronger biceps will also come in handy during functional movements, such as picking things up or pulling things in everyday life. Improved grip strength will also come into play when going about daily tasks.

Accessible Exercise

Although barbell curls aren’t necessarily the greatest movement to be training your biceps, they are one of the most accessible lifts. All it takes is a straight bar and some weight plates. If you don’t have a barbell, a pair of dumbbell curls or kettlebell curls can also provide a solid alternative. The mechanics of the movement will change slightly, but curls, in general, don’t take a lot of equipment and are relatively easy to learn and perfect.

Preventing Common Injuries

Since the biceps are primarily responsible for elbow flexion, they have a lot of input on the health of your elbow and wrist. For one, stronger biceps will help your grip when it comes to pulling movements and loaded carries. Furthermore, strong biceps can also help you avoid unnecessary strains on the biceps and grip issues. All this boils down to having strong, bigger, and healthier arms.

How To Barbell Curl

Before you begin, you’ll want to make sure you’re properly warmed up. This will loosen up your muscles and get your blood pumping, which will help your performance. All you need is a barbell and the weight plates you’ll be using.

Don’t choose a weight that’s too heavy—especially if you’re just starting out with barbell curls. In fact, it’s probably best you do them with just the barbell if it’s your first time. This will help you get the form down perfectly before moving on to more strenuous weights.

1. Hold the barbell slightly wider than hip-width apart, with an underhand grip (palms will be facing away from you). The grip can vary, however, depending on arm length and the muscles you’re targeting. Let your arms hang down with the load, but make sure that your shoulder blades are pulled back—you do not want to be hunched over at any point during this lift. Standing tall with your chest out and shoulders back will ensure that your biceps are fully exposed to the load.
2. Before you initiate the actual movement, you’re going to want to squeeze the bar tightly. A good way to go about this is to squeeze your pinkies against it, as if you’re trying to snap the barbell. A tighter grip will help your elbows stay closer to your body throughout the lift, which should help with the transfer of power. Additionally, you’ll also better engage the forearm muscles, which will in turn help to activate the actual targets—the biceps.
3. Next comes the actual movement in the lift. You’re going to want to engage your biceps and begin curling the bar upward. However, take into account the positioning of your elbows. They should be moving just a bit in front of your torso, rather than in line with it, since this will better activate your biceps. Along with the elbows, make sure that your shoulders are pulled back. They’ll very slightly move when your elbows come forward, but they shouldn’t move much—instead, squeeze them together behind you, and keep your chest high.
4. You want to make this lift count for your biceps, so you need to ensure that your biceps are contracting enough. The bar should continue upward until you feel you’ve maxed out your bicep engagement, which will likely be when the bar reaches 1 to 2 inches from your shoulders. Once you’ve reached the sweet spot of maximum contraction, that’s where you want to pause for a second or two. Don’t just reach the top of the movement and quickly lower the weight back down.
5. Once you’ve contracted your biceps at the top of the movement, it’s time to go back down to the starting position. However, you don’t want to go down too fast. A lot of muscle development happens due to the eccentric contraction of muscles—when they lengthen. This is why it’s important to take 2 to 3 seconds to lower the bar back down, as difficult as it may be.
6. Once you’ve reached the bottom of the movement, repeat for the desired amount of reps. Done with perfect form, you’ll probably not be able to curl as much as you might be used to, but the hard work will pay off with more gains.

Programming into Your Routine

When deciding how many reps and sets to complete, your goals are going to be the defining factor. If you’re a beginner lifter that’s training for general wellness, 2 to 3 sets of 8 to 12 reps is a good place to start.

This is because the bicep muscle is relatively small, and it’ll better respond to lower loads spread over a higher number of repetitions. If you’re aiming for hypertrophy and simply bigger arms, doing 5 to 8 sets of 8 to 12 repetitions is recommended. You should also place a special emphasis on the muscular contraction, completing each rep with intention.

On the other hand, strength goals look a bit different.

This time, you won’t necessarily be looking for a lot of volume, but instead a lot of intensity. This means that the loads will be higher, but your reps and sets will be lower. It’s recommended that one does 4 to 6 sets of 4 to 8 repetitions if training for strength. Just keep in mind that the bicep is a smaller muscle, so don’t overload it too much.

When to Train with Barbell Curls

You might also be wondering when during a routine should barbell curls be implemented. This comes down to whether you’re doing a separate arm day, or an arm day combined with another muscle group.

For example, combining an arm with your chest or back means you should wait until later to complete barbell curls. Your larger muscles will need most of your energy when performing big lifts, and so it’s a good idea to put them first.

If you have a day devoted solely to arms, the recommendation is to do barbell curls first. This is because you’re going to be able to lift a lot of weight with the barbell curl, and so putting it first will give you the best results in your training and development.

Tips for the Perfect Barbell Curl

Although the barbell curl is a relatively simple movement, getting the most out of it means performing it with the best form possible. There are several key areas to pay attention to if you want your biceps to really feel the burn—and really experience some serious gains.

Optimizing Grip Width

Since there isn’t a one-size-fits-all answer for the perfect grip width, many people have issues finding the one that works for them. The primary thing to look at is whether the position is comfortable, and that will largely depend on your individual physical features, especially as they relate to the length of your arms.

You definitely don’t want to feel any pain when curling, so that’s priority number one. And the more comfortable your lift, the more you’ll be able to load on the barbell. The width of shoulders also comes into play, since the wider the shoulders, the more natural a wide grip will feel.

Looking further than your body’s proportions, you can also change the width of the grip based on your training goals. For example, a wide grip will place a greater focus on the inner head of the bicep. On the other hand (or head), a narrower grip will emphasize the outer head and muscle fibers of the bicep.

Range of Motion and Bar Path

While barbell curls are useful, it’s very easy to cheat using either momentum or completing half reps. You need to be performing a full range of motion, where the forearms press into the biceps and the bar comes within inches of your shoulders. The weight should then be lowered all the way back down into the starting position in a controlled manner, over the course of 2 or 3 seconds.

Completing a full range of motion with intent will recruit far more muscle fibers than with half reps since half reps will ignore entire parts of your bicep muscle fibers. Not only will this lead to increased muscle growth in the long run, but it’ll also increase your chances of injury. After all, this is an isolation exercise, and you want to be isolating the bicep as best you can. If that means lowering the load, then that’s what you should do.

There is an alternative to the barbell curl called the drag curl, which has the lifter keep the barbell as close as possible to their body as it’s curled up. However, even though it may give you a good pump, this isn’t what you’re going for in the conventional barbell curl.

With optimal form, the barbell should actually arc forward as it goes across your body, with the front delts and elbows moving forward slightly along with it. This comes down to the basic function of the bicep: shoulder flexion. Although you don’t want to be swinging any weights, you do want the bar path to arc so that your bicep experiences as intense of a contraction as possible.

Keep Volume and Intensity in Check

The last key point is to control the load you train with. This is both in terms of intensity and volume. When it comes to intensity, choosing a weight that’s too heavy leads to the large majority of form breakdown. In the end, you’re not chasing the number of reps you can complete or the load that you can curl—you’re going after perfect form which will lead to optimal muscle growth and strength gain.

Leaving your ego at the door and opting for lighter weights is highly recommended if you find your form suffering in the last few reps of every set. The side of this is the training volume. Although training for muscle hypertrophy necessitates higher numbers of sets and reps, you also don’t want to overdo it in this department.

Overdoing will be different for everyone, depending on fitness level, the capacity for recovery, and the quality of one’s diet. Doing too much too fast will get in the way of consistent gains and might even hurt your development. This will mostly be due to the physical toll that overtraining can take, and also to the mental demotivation that’ll take hold after sticking to one exercise for too long.

Spreading out your sets over the week is a good starting point. You’ll be much better off doing 5 sets twice a week that are high quality, than 10 sets in one gym session that get progressively worse due to muscle fatigue. Adding in other biceps exercises that hit the muscle slightly differently is also a good idea. Just remember that the bicep is a small muscle, and overtraining is something you need to consider.

Barbell Curl Variations and Alternatives

Although the standing barbell curl is a workhorse of an exercise, there are many other alternatives that can provide either a different or better focus on the target muscle. As we looked at above, even widening the grip to shoulder-width or more in a wide-grip barbell curl will change the muscle emphasis in the upper arms.

Using an EZ bar instead of a straight barbell is also a great way to make weightlifting more comfortable and hit the biceps at a slightly different angle.

Instead of the barbell bicep curl, you can also opt for something like the  preacher curl or the hammer curl. Both of these can provide more bicep activation than the regular bicep curl and will build muscle at a faster rate.

Curling to a Bigger, Stronger Body

The barbell curl is a juggernaut of an exercise when looking to craft bigger biceps, and a more generally more powerful upper body. Although it takes a lot of attention to form and hard work, the results will speak for themselves.

If you’re looking to turbocharge your gains—whether in the bicep department or in general—consider taking high-quality supplements formulated for  muscle growth.

No supplements will provide a complete alternative to hard work or good food, but they will give you an edge when you’re looking to fill out your shirt sleeves as much as possible.