The first time I heard about this exercise, I was confused.
Then, once I found out what these actually were, I realized why people were talking about them. It’s a phenomenal exercise to target and isolate the biceps, if you do it correctly.
Now, if you’re not sure how to do them just yet ... don't worry. That’s what I’m here for; to teach you.
Not only will I teach you that, but I’ll also cover some common mistakes people make when doing them. First, let’s go over what a spider curl actually is...
What Are Spider Curls, and How Are They Different From Regular Curls?
Spider curls are a type of bicep curl where you lay on an incline bench, and do curls with your arms freely hanging down toward the ground.
It’s not a very complicated exercise, but it is a little different than a traditional curl. Allow me to explain, so you know what to expect...
In most variations of the bicep curl, you have some support for your upper arm to push against for leverage.
In a standing bicep curl, you might not realize it, but you activate your lats to hold your upper arm in place at your side. This gives you more leverage to pull more weight.
In a concentration curl, you set your upper arm against your leg for support.
In a preacher curl, you lay your arms on a pad for support.
In each of these cases, you have a bit of a mechanical advantage to lift the weight. That’s not the case with spider curls.
When doing spider curls, your arms hang freely below you at an angle where you have a little less leverage. You have no support for your upper arms, and your biceps get a good stretch at the bottom. This makes it more difficult to pull the weight up.
There’s another piece to this exercise that makes it harder...
Normally, people end up recruiting their deltoids to help pull the arm up in front of them. Bringing your arms in front of you while doing a bicep curl makes it easier to curl the weight up.
The bicep does this as well to a small degree, but it's not the same. When you see someone's upper arms way in front of their body during a bicep curl, the deltoid is doing a lot of the work.
The spider curl makes involving your deltoid very difficult. So if your arms have less support, and your deltoids are not a factor, your biceps have to work harder to move the weight.
That is, as long as you do them correctly.
There is always a way to cheat the rep, but you’ll only be cheating yourself out of the benefits of the exercise if you do.
To put it simply, the spider curl is harder than a normal curl, but the difficulty makes it better for muscle growth, in many cases. So in other words … if you want to start working toward building arms like Arnold, you better be doing spider curls!
What Muscles Do Spider Curls Work?
Spider curls are known for their ability to isolate the biceps, but other muscles get some work too ... especially if you consider the different variations and grips you can do.
Every grip you use for spider curls will target the biceps in some way ... with palms facing forward targeting them the most. Changing your grip switches the emphasis to another muscle though.
If you turn your palms from facing forward to facing each other, you emphasize the brachialis. This muscle lies beneath the biceps and can help increase arm thickness.
If you turn your palms again to face away from you, you are now targeting the brachioradialis. This muscle gives a lot of thickness to the upper forearm near the elbow.
All these muscles work together in every curl, but which muscle gets worked the most depends on your grip. Regardless of which grip you choose though, it’ll help you develop some big thick muscles in your arms.
So, for the most part ... spider curls are designed to primarily train your biceps.
But now that you know which muscles we’re working with, let’s dive into how to properly do the spider curl.
How to Do the Spider Curl
Setting up to do spider curls is simple. The execution is where some people go wrong, but I’ll be as thorough as I can so it doesn’t become an issue for you.
Step 1: Locate Equipment
All you need is a bench set up at a 45-degree angle and a pair of dumbbells.
Step 2: Choosing the Correct Weight
This is not an exercise to try to go super heavy on. If you do standing bicep curls with 40-pound dumbbells, I wouldn’t try that much here.
Remember, you have less of a mechanical advantage in the spider curl. That means the heavier you go, the more likely you are to cheat the rep in order to get the weight up.
Start with a weight you can complete 10-15 reps with fairly easily. That way, you can get your form down and feel how the movement is supposed to feel.
Step 3: Take Position on the Bench
With your dumbbells in hand, lay your chest on the upper part of the bench. Try to keep your legs straight and the balls of your feet on the ground.
Your dumbbells should be hanging freely below the bench without touching anything.
Also be sure to pull your shoulders down and back. This puts them in a more stable position when you have weight in your hands.
Step 4: Choose Your Grip
Remember, the direction your palms face during a spider curl matters. It helps determine which muscle is used most to execute it.
If you want to focus on your biceps:
Keep your palms facing forward throughout the entire set.
Or start with your palms facing each other, and rotate the palms forward as you curl up.
If you want to build your brachialis to help with arm thickness: Keep your palms facing each other throughout the entire set.
If you want to build your brachioradialis to help with forearm thickness: Keep your palms facing away from you throughout the entire set.
If you want to focus on all 3 in every rep, you can try doing zottman spider curls.
This variation requires your palms to face forward on the way up, then you turn your wrists at the top so the palms face the ground on the way down.
Step 5: Execute
With your arms hanging straight down, engage your biceps in order to curl the weight up as high as you can get it.
When you reach the top of the exercise, squeeze your biceps hard for a second, and then slowly return back to the starting position.
Repeat for reps.
Common Mistakes to Consider
Do your best to keep your upper arms from moving in any direction throughout the exercise. This helps to keep the emphasis on the biceps.
The most common mistake I see when doing the spider curl is pulling the upper arms back toward your body like you would when doing a row. This puts more emphasis on the lats, and your biceps don’t have to work as hard to curl the weight.
But ... if you’re doing the spider curl to grow your biceps, performing it this way will only make it harder to see progress.
Now you know how to execute the spider curl properly. It’s truly a great exercise to build up your arms, and it’s pretty fun too.
There are so many ways to train your muscles, and it’s good to switch up the exercises when planning your workouts. Each one will hit the muscle a different way, and switching it up on your body is the key to seeing progress.
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If you have questions, or need help, don't hesitate to reach out! We have a full team of NASM Certified Personal Trainers and Certified Nutrition Coaches who are more than happy to get you on track for free! Just give us a call at 1-800-409-9732 or send us an email at CustomerService@1stphorm.com anytime!