🔥 What Are Skull Crushers?

Skull crushers—also known as lying tricep extensions—are an isolation exercise that primarily targets the long head of the triceps. The movement involves lowering a barbell, dumbbells, or an EZ-bar toward your forehead (hence the name), then extending your elbows to lift it back up.

Because the arms move through a deep stretch under tension, skull crushers are one of the best exercises for maximizing muscle hypertrophy and improving the overall shape and size of the triceps.

💪 Muscles Worked During Skull Crushers

Skull crushers mainly target the triceps brachii, which consists of:

• Long Head – Most activated during skull crushers; contributes to arm mass

• Lateral Head – Helps with arm width and the “horseshoe” shape

• Medial Head – Provides stability and assists in all tricep movements

This exercise is especially effective in hitting the long head, which is responsible for most of the triceps’ total size.

🏋️‍♂️ How to Do Skull Crushers (Step-By-Step Form)

1. Set Up Your Equipment

Choose an EZ-bar, straight barbell, or dumbbells.
Lie back on a flat bench with feet planted firmly on the ground.

2. Starting Position

• Hold the bar or dumbbells above your chest.

• Keep your elbows pointed toward the ceiling.

• Maintain a slight backward angle to keep tension on the triceps.

3. Lower the Weight

• Bend your elbows slowly.

• Lower the weight toward your forehead or just behind your head.

• Keep elbows tight and stable—don’t allow them to flare out.

4. Extend and Squeeze

• Straighten your arms to lift the weight back up.

• Squeeze the triceps at the top.

• Keep movement controlled, never rushed.

5. Breathing

• Inhale as you lower the weight.

• Exhale as you push back up.

🎯 Benefits of Skull Crushers

🔶 1. Builds Massive Tricep Size

Skull crushers place the triceps under heavy stretch, activating deep muscle fibers necessary for hypertrophy.

🔶 2. Superior Long-Head Activation

The long head contributes heavily to overall arm size—skull crushers are one of the top exercises to target it.

🔶 3. Improves Pressing Strength

A stronger triceps means a stronger bench press, shoulder press, and dips.

🔶 4. Versatile and Beginner-Friendly

You can perform skull crushers with barbells, dumbbells, cables, or resistance bands.

🔶 5. Boosts Arm Definition

This exercise helps shape the arms and adds thickness to the upper triceps area.

🪢 Skull Crusher Variations

1. EZ-Bar Skull Crushers

• Most popular version

• Easy on the wrists

• Great for building size and strength

2. Dumbbell Skull Crushers

• Allows greater range of motion

• Fixes strength imbalances

• Excellent for muscle symmetry

3. Incline Skull Crushers

• Works the long head more intensely

• Provides deeper stretch for growth

4. Decline Skull Crushers

• Shifts tension to lateral and medial heads

• Great for creating tricep width

5. Cable Skull Crushers

• Constant tension throughout movement

• Reduced joint stress

• Smoother motion than free weights

6. Single-Arm Skull Crushers

• Improves elbow stability

• Enhances mind-muscle connection

🚫 Common Mistakes to Avoid

❌ Letting Your Elbows Flare

This reduces tension on the triceps and stresses the shoulders.
Solution: Keep elbows tight and pointing upward.

❌ Using Too Much Weight

This leads to poor form and increases injury risk.
Solution: Start light and progress gradually.

❌ Dropping the Weight Too Quickly

Fast reps increase risk of hitting your forehead (hence the name).
Solution: Use slow, controlled reps.

❌ Moving the Arms Back and Forth

This turns the exercise into a press rather than an extension.
Solution: Only bend at the elbows.

❌ Not Using Full Range of Motion

Partial reps reduce activation of the long head.
Solution: Lower the weight fully while keeping shoulders stable.

📈 Programming Skull Crushers for Maximum Results

🔥 For Muscle Growth (Hypertrophy)

• 3–4 sets

• 8–12 reps

• Slow tempo + stretch + squeeze

🔥 For Strength

• 3–5 sets

• 5–8 reps

• Use EZ-bar for heavier loads

🔥 For Definition

• 3–4 sets

• 12–20 reps

• Use cable variations for constant tension

🔥 Frequency

Train skull crushers 1–2 times per week on push or arm days.

💥 Tips to Maximize Tricep Activation

• Keep the weight directly above your head, not your chest.

• Use a slight decline or incline bench to target different tricep heads.

• Maintain a strong mind–muscle connection—focus on stretching and squeezing.

• Try drop sets, rest-pause sets, or supersets with pushdowns for maximum pump.

• Warm up elbows before heavy sets to prevent strain.

🔚 Final Thoughts: Why Skull Crushers Should Be in Your Routine

Skull crushers are undoubtedly one of the most effective exercises for building thicker, stronger, and more defined triceps. Their ability to emphasize the long head makes them essential for anyone aiming to grow overall arm size. When performed with proper form and consistency, skull crushers can significantly enhance your pressing strength, arm aesthetics, and total upper-body performance.

Add them to your workout routine and watch your tricep size and definition skyrocket.