What Are Dumbbell Spider Curls?

Dumbbell spider curls are an arm exercise where you brace your upper body against an incline bench while curling a dumbbell in each hand. The bench stabilizes your body so that only your arms move during the exercise.

In addition, the way your arms hang in front of you changes how the muscles work compared to other bicep exercises.

Dumbbell Spider Curl Muscles Worked

As with all arm curl exercises, a dumbbell spider curl primarily targets the bicep muscles. However, it’s also important to know that the bicep is actually made up of two smaller muscles or heads.

Specifically, these two parts are called the long head and short head of the bicep. And there is a third muscle on your outer arm called the brachialis. The long head makes up the outer part of your bicep, while the short head makes up the inner part.

In terms of shape, the short head helps give your biceps thickness and width. So dumbbell spider curls are great for widening your biceps.

Dumbbell Spider Curl Mechanics

The dumbbell spider curl targets your inner bicep in a couple of different ways, and each has to do with the exercise mechanics and body position.

First, your hand position has a lot to do with which muscles get worked in bicep curls. And the supinated or palms-up grip helps activate the inner bicep.

Second, the angle of your upper arm to your torso also changes the muscles activated. In this case, having your arms angled in front of your body helps target the short head.

Dumbbell Spider Curl Benefits & Limitations

Your arms are automatically out in front of your body with spider curls. And you can choose to use a palms-up grip. So this exercise can add to bicep thickness in two ways.

In addition, the incline bench supports your upper body, making it more difficult to cheat using momentum. Finally, each arm must work independently so it helps prevent the dominant arm from taking over.

Of course, there are limitations to the dumbbell spider curl as well. For one, you won’t be able to go as heavy as you would with traditional barbell or dumbbell curls. And it can be challenging to master the technique at first.

Pros

• Places arms in front of the body to target the short head of the bicep
• Able to use an underhand grip to target the inner bicep further
• Prevents unnecessary movement and eliminates momentum to isolate the bicep
• Each arm works independently

Cons

• Not the best exercise for heavy weights
• Challenging to keep your upper arm from swinging

How To Do Dumbbell Spider Curls

To begin, set an incline bench at 30 degrees to 45 degrees. Next, grab a pair of dumbbells and lie face down on the bench with your chest resting at the top. Then let your arms hang straight down to the floor.

From this starting position, curl the dumbbells toward the top of the bench while keeping your palms up. Now lower the weight until your arms are straight again.

After your set, drop the dumbbells or dismount and set them on the floor.

To recap, here are the step-by-step directions:

1. Set up the incline bench with the backrest at 30-45 degrees
2. Lie chest down with the dumbbells at arm’s length
3. Curl the weight while keeping your upper arms relatively still
4. Lower the weight until your arms are almost straight
5. Repeat for the desired number of reps

Tips for Good Form

The description and video above should give you a good idea of how to do dumbbell spider curls properly. But here are some additional tips to really help you isolate your biceps.

A shallower angle works the inner head more, but the dumbbells may start hitting obstructions if you get too flat. That’s why 30-45 degrees is the ideal bench setting.

Dumbbell Spider Curl Variations

As with most bicep exercises, there are multiple ways to do spider curls using different equipment. So below is a list of exercise variations you can do with free weights or cables.

Single Arm Dumbbell Spider Curl

So far, I’ve shown you how to do dumbbell spider curls with both arms simultaneously. But you can also do this exercise with each arm separately.

One option is using two dumbbells but alternating arms with each rep. Or you could use a single dumbbell and perform an entire set with one arm at a time.

Hammer Dumbbell Spider Curls

We talked a lot about using a palms-up grip during dumbbell spider curls. But you can choose to use a neutral or hammer grip as well. In other words, you keep your palms facing in and thumbs up throughout the exercise.

This hand position brings the outer long head of the bicep into the exercise. So it works multiple heads but doesn’t target either particularly well.

Barbell Spider Curls

You can do spider curls with a standard barbell if you don’t have dumbbells. The straight bar forces you to use a completely supinated grip, which is great for the inner bicep.

However, the torque on your wrist can cause discomfort or forearm pain.

EZ Bar Spider Curls

An EZ bar has a curved handle that lets you use a palms-up grip without putting excess stress on your wrists. And EZ bar spider curls are probably the most common variation of this exercise.

For the most part, the exercise is the same as you would do for dumbbells. But here is another short video showing you how to do EZ spider curls.

Dumbbell Spider Curl Alternatives

Of course, you don’t have to use spider curls to target your inner biceps. And several other great exercises achieve similar muscle activation.

Preacher Curls

A preacher bench is designed to place your upper arms in front of your body as you perform curls. And when done with an underhand and wide grip you can further isolate the inner head.

In addition, the preacher bench holds your arms in place so you must use strict form.

Concentration Curls

Concentration curls also involve holding your arm in front of your torso. And you can rest your upper arm on your knee like a preacher curl or just hold it in space like a spider curl.

Again, the body position and mechanics of the concentration curl are ideal for working the short bicep head. Below is an image of Arnold Schwarzenegger doing dumbbell concentration curls.