Spider Curl

The spider curl is a biceps isolation exercise performed lying chest-down on an incline bench, set at roughly 45 degrees, with your arms hanging straight down in front of you. Because your chest is locked against the pad and your arms have nothing to rest against, there's no way to swing your hips, shoulders, or torso to help move the weight — the biceps have to do the entire rep on their own. That makes the spider curl one of the strictest biceps builders available, with a long, complete range of motion from a full stretch at the bottom to a hard contraction at the top. This guide covers exactly how to spider curl safely, the muscles it targets, how to program it, the mistakes that turn it into a half-rep swing, and how it compares to the preacher curl.

What muscles does the spider curl work?

Lying chest-down on an incline bench with your arms hanging freely in front of you removes almost every way to cheat a curl — there's no torso to swing and no bench to rest your elbows on the way a preacher curl provides. The biceps brachii drives the lift essentially alone, with the brachialis and brachioradialis assisting elbow flexion throughout. Because the arms hang completely unsupported, the exercise also demands more from your grip and forearm flexors than a supported preacher curl does.

How grip and angle change muscle activation

Direct EMG research isolating the spider curl specifically is limited, but the biomechanical principle — an unsupported, prone arm position — is well documented by strength coaches and exercise classification resources. Treat any specific muscle-head claim as a general tendency rather than an exact percentage.

• Prone, arms-hanging setup: Forces the biceps and brachialis to control the weight through the entire range with no assistance from body momentum, unlike standing curls where hip and shoulder sway can help.
• Full stretch-to-contraction range: Curl variations trained through a complete, unsupported range of motion have shown strong hypertrophy responses in controlled studies of similar isolation movements.

Based on EMG research. [1]

How do you do the spider curl?

To do the Spider Curl: set an adjustable bench to roughly 45 degrees and lie face-down with your chest fully supported against the pad; hold a dumbbell in each hand with your arms hanging straight down, palms facing forward, feet planted for stability; without letting your upper arms swing or drift, curl the dumbbells up by flexing at the elbows only; curl until your biceps are fully contracted, then pause and squeeze for a moment at the top.

1. Set an adjustable bench to roughly 45 degrees and lie face-down with your chest fully supported against the pad.
2. Hold a dumbbell in each hand with your arms hanging straight down, palms facing forward, feet planted for stability.
3. Without letting your upper arms swing or drift, curl the dumbbells up by flexing at the elbows only.
4. Curl until your biceps are fully contracted, then pause and squeeze for a moment at the top.
5. Lower the dumbbells back down slowly over 2–3 seconds to a full, straight-arm stretch.
6. Reset briefly at the bottom without letting the weight yank your shoulders forward before starting the next rep.

What are the key spider curl form cues?

Chest locked to the pad

Keep your chest fully supported against the bench for the entire set — lifting off to help the weight up defeats the exercise's purpose.

Elbows fixed

Keep your elbows in roughly the same position throughout the rep, just in front of your shoulders, rather than letting them swing back and forth.

Full range

Lower to a complete, straight-arm stretch and curl to a full contraction each rep — partial reps waste the exercise's biggest advantage.

Slow eccentric

Control the lowering phase over 2–3 seconds instead of letting the dumbbells drop, since the unsupported arm makes a fast eccentric harder on the elbow.

Feet planted

Keep your feet flat on the floor or braced against the bench legs for stability so your body doesn't rock during the set.

Breathing & tempo: Exhale as you curl up and inhale as you lower. Use a controlled 2-1-3 tempo (2 seconds up, 1 second squeeze, 3 seconds down) — the slow eccentric matters more here than in almost any other curl variation because there's no pad to catch a sloppy descent.

How should you warm up for the spider curl?

Do 1–2 light sets of 12–15 reps with light dumbbells to prime the elbow flexors, since the unsupported arm position loads the elbow through a longer range than a preacher curl or standing curl.

What are the most common spider curl mistakes?

• Lifting the chest off the pad — Keep your chest pinned to the bench for the whole set. If you need to lift off to finish a rep, the weight is too heavy — drop it and rebuild strict reps.
• Letting the elbows swing — Keep your elbows in a fixed position roughly under your shoulders. Swinging elbows turns the movement into momentum rather than strict biceps work.
• Rushing the eccentric — Lower the dumbbells over a full 2–3 second count. Dropping the weight quickly in this unsupported position is the most common cause of spider-curl elbow soreness.
• Using too heavy a weight — Because there's no pad to rest on, the spider curl exposes an overloaded set faster than other curl variations. Drop the weight until you can complete a full range with strict control.
• Cutting the bottom stretch short — Lower all the way to a straight-arm position each rep instead of stopping halfway to make the set feel easier.

Why does the spider curl hurt — and how do you fix it?

Discomfort during spider curls almost always traces back to a rushed eccentric or too much weight for a fully unsupported arm. Match your symptom to the fix below, and stop and see a professional if pain is sharp or persistent.

How many sets and reps should you do?

Choose your sets and reps by goal: heavier and fewer reps for strength, moderate for muscle size, lighter and higher for endurance.

RPE / RIR: Keep most sets around RPE 7–8. Because there's no pad or bench to catch a failing rep, pushing to true RPE 10 on the spider curl carries more elbow risk than on a supported preacher curl — leave a rep or two in reserve on most sets.

Program the spider curl as an accessory after your main compound lifts, two to three times a week. It pairs naturally as a superset with a triceps isolation move, and because it emphasizes full-range strict tension, it works well as a finisher after heavier curling work earlier in the session.

How often should you spider curl and where does it fit?

Train the Spider Curl 2–3 sessions per week, placing it after compound pulling work and heavier curl variations, as a strict finisher for the biceps.

• Frequency: 2–3 sessions per week
• Best split days: Pull day (Push/Pull/Legs), Arm day (bodybuilding split), Upper day (Upper/Lower)
• Where to place it: After compound pulling work and heavier curl variations, as a strict finisher for the biceps

Superset it with a triceps isolation exercise to keep arm day time-efficient.

How do you progress the spider curl?

To curl more weight on the spider curl, train it 2–3×/week with a genuinely full range, prioritize a slow, controlled eccentric over adding load, and build the elbow's tolerance to the unsupported stretch gradually.

What's the right range of motion?

Lower to a full, straight-arm stretch and curl to a complete contraction at the top, pausing briefly to squeeze. Because there's no pad limiting the bottom position the way a preacher curl has, control the descent carefully rather than letting gravity take over.

What are the benefits of the spider curl?

• Removes essentially all momentum, making it one of the strictest biceps isolation exercises available
• Trains a long, complete range of motion from full stretch to full contraction
• Works well as a finisher after heavier curl variations earlier in a session
• Available as a unilateral exercise to address left-right strength imbalances
• Builds grip and forearm endurance as a secondary benefit from the unsupported hang

Who should do it: Intermediate and advanced lifters looking for a strict, momentum-free way to finish biceps training, and bodybuilders chasing a complete range of motion and a well-rounded arm. Lifters with current elbow tendon pain should start with a supported preacher curl instead until symptoms resolve, since the unsupported arm loads the elbow through a longer range.

Is the spider curl safe?

The spider curl is safe for most healthy lifters when the weight is appropriate for a fully unsupported arm and the eccentric is controlled, but it's less forgiving of sloppy form than a preacher curl since there's no pad to limit the bottom position. Most problems come from rushing the lowering phase with too much weight.

Elbow tendon soreness

Reduce load and slow the eccentric significantly, or substitute a supported preacher curl until the area settles.

Chest or rib discomfort on the pad

Use a flatter bench angle or add padding, and reduce time spent in the prone position if needed.

Wrist discomfort

Keep the wrist neutral and reduce load; consider an EZ-bar spider curl for a friendlier grip angle.

Spotting: A spotter isn't strictly necessary, but having someone nearby to help you rack the dumbbells at the end of a hard set is a reasonable precaution since your chest is pinned to the bench.

How do grip and stance change the spider curl?

• Dumbbells, palms forward (standard): Full supination for maximum biceps involvement — the default spider curl setup.
• EZ bar: A semi-pronated grip that's easier on the wrists while allowing a heavier bilateral load than dumbbells.
• Single-arm dumbbell: Lets you focus fully on one side's range and mind-muscle connection.

Spider Curl variations

How does the spider curl compare?

Spider Curl vs. Preacher Curl

Both lock the torso in place and remove momentum, but the preacher curl supports the upper arm on a pad while the spider curl leaves the arm hanging completely free. The preacher curl is generally easier to load heavier and control; the spider curl demands more grip and forearm stability and gives an uninterrupted, longer range of motion.

Spider Curl vs. Incline Dumbbell Curl

The spider curl is performed prone with the arms hanging in front of the body; the incline curl is performed seated with the arms hanging behind the body. Both remove momentum and add stretch, but they load opposite ends of the biceps' length — using both across a week trains a genuinely longer combined range.

Spider Curl alternatives

Estimate your spider curl 1RM

Enter a weight and the reps you hit with it to estimate your one-rep max (Epley formula), then see your training percentages.

How many calories does the spider curl burn?

Calories depend on your bodyweight and how hard you train. Resistance training has a MET value of about 3.5. Enter your bodyweight and minutes to estimate the burn (calories = MET × kg × 3.5 ÷ 200 × minutes).

Spider Curl strength standards

Approximate one-rep max per dumbbell as a multiple of bodyweight, based on aggregated lifter data for strict, unsupported curl variations. Because the spider curl removes all momentum, these numbers run below standing curl figures — treat them as motivating benchmarks, not hard targets.

By age: Curl strength tracks training age more than age in years through your 40s. Lifters in their 40s can aim for about 90% of these numbers, 50s about 80%, and 60s+ about 65–70%, adjusting for elbow and joint health.

What counts as a good rep?

A spider curl rep counts when you lower the dumbbell to a full, straight-arm stretch and curl it back to a complete contraction, without lifting your chest off the pad or swinging your elbows to help move the weight.

References

1. Zabaleta-Korta A, Fernández-Peña E, Torres-Unda J, et al. Regional hypertrophy: the effect of exercises at long and short muscle lengths in recreationally trained women. Journal of Human Kinetics (NIH/PMC), 2023
2. How to Do Spider Curl: Muscles Worked & Proper Form. StrengthLog
3. How To Do Spider Curls. ATHLEAN-X
4. Spider Curl — video exercise guide and tips. Muscle & Strength
5. Barbell Prone Incline Curl (Spider Curl) — classification, muscles and instructions. ExRx.net
6. Marcolin G, Panizzolo FA, Petrone N, et al. Differences in electromyographic activity of biceps brachii and brachioradialis while performing three variants of curl. PeerJ (NIH/PMC), 2018
7. Bicep Tendonitis: Pain, Causes, Side Effects & Treatment. Cleveland Clinic