Spider Curls (also called Prone Incline Curls) are a biceps exercise popularized by the first Mr. Olympia Larry Scott who said the exercise really helped build his biceps peak.
The name supposedly came from the original custom bench Larry used to do these curls that had 8 legs like a spider.
While building bigger biceps typically means doing compound exercises such as heavy barbell and dumbbell curls, it’s easy to cheat on those to keep the weight moving upward by using the front delts.
At the top of the curl the front delts can also help hold the weight in position removing a lot of tension from the biceps muscle making a full contraction difficult.
Because the biceps muscle attaches at the shoulder, one of the muscle’s function is to extend the arm forward and upward (somewhat similar to the front delts).
To get a full biceps contraction you need to have the arm extended upwards (elbow near the same height as the shoulder) during the curling motion.
Spider Curls are more of a biceps isolation exercise because the arms will remain extended forward during the exercise, essentially removing the front delts from helping move the weight.
Because the biceps muscle is better isolated you will most likely need to use lighter weights than normal.
Unfortunately, finding the original or similar bench to do Spider Curls in a gym today will be difficult so you will most likely need to use an incline bench or steep preacher curl bench instead to try and replicate the exercise.
How to Do Spider Curls (Prone Incline Curls)
- Lay against the steep preacher curl bench or an incline bench with your chest on the pad (prone position). If using an incline bench, set the incline as low as comfortable. The closer your upper body is to being parallel with the ground (as with the original bench), the more isolated the biceps will be allowing for a stronger peak contraction.
- Let your arms hang down towards the ground. You will not be able to get a great biceps muscle stretch at the bottom of the rep because the arms are in front of the body. The arms need to be behind the body for a full stretch. Therefore, it’s important to make sure to fully extend the arms at the bottom of the rep so that you don’t further limit the already reduced range of motion.
- You want to keep the upper arm pointing at the ground through the whole exercise. Resist the urge to cheat by pulling your upper arm back down towards your feet or pushing it forward which can make it easier to move the weight.
- You can use either a barbell (straight or cambered) or dumbbells. A straight barbell can be harder on the wrists by locking them in position but it also keeps the palms facing upward (supinated) which is needed for a full biceps contraction. If you use dumbbells, make sure to turn the palms upward, especially at the top of the rep.
- If you use dumbbells you can curls both arms at the same time or alternate – experiment to see which feels better. You can also use the constant tension method for longer time under tension by keeping the opposite arm in the contracted position while the other dumbbell is lowered and curled back up.
- Pause and squeeze hard at the top of the curl to take full advantage of the peak contraction this exercise allows. Most people find that lighter weights with higher reps work best for getting a full contraction.
- If you use a close grip by having your hands closer together than your elbows are, you will put even more tension on the long head of the biceps muscle. The long head is what gives the biceps their “peak”.