The biceps brachii literally means "two-headed muscle of the arm." Understanding these two heads helps you train more effectively. Here's a clear breakdown.
The Two Heads
Long head:
• Location: Outer (lateral) part of your arm
• Origin: Supraglenoid tubercle (above the shoulder socket)
• Appearance: Creates the "peak" when flexing
• Special feature: Passes through the bicipital groove of the humerus
Short head:
• Location: Inner (medial) part of your arm
• Origin: Coracoid process of the scapula
• Appearance: Creates width and thickness
• Shorter path from shoulder to elbow
Both heads merge into a single tendon that attaches to the radius bone at your elbow.
What Each Head Does
Both heads perform the same functions:
Elbow flexion: Bending your elbow (curling motions)
Forearm supination: Turning your palm upward
Shoulder flexion: Raising your arm forward (minor role)
The difference is in their relative contribution based on arm position, not their function.
How to Emphasize Each Head
Long head emphasis (outer bicep, peak):
Position: Arm behind your body (shoulder extension)
Exercises:
• Incline dumbbell curl
• Behind-the-back cable curl
• Drag curl
• Narrow grip curls
Short head emphasis (inner bicep, width):
Position: Arm in front of your body (shoulder flexion)
Exercises:
• Preacher curl
• Spider curl
• Concentration curl
• Wide grip curls
Why This Matters for Training
If you only do standard standing curls, you're training both heads about equally. That's fine for general development.
But if you want to:
• Build a bigger peak → Add more long head exercises
• Build more width → Add more short head exercises
• Address a lagging area → Prioritize exercises for that head
Sample Balanced Routine
Long head: Incline dumbbell curl – 3 sets x 10-12
Short head: Preacher curl – 3 sets x 10-12
Both heads: Standing barbell curl – 3 sets x 8-10
Brachialis: Hammer curl – 2 sets x 12-15
This ensures complete bicep development across both heads plus the supporting brachialis.
Common Questions
"Which head is more important?"
Neither—both contribute to arm size and function. Train both for balanced development.
"Can I only train one head?"
No, both always work together. You can only shift emphasis.
"Will long head work give me a peak?"
It will maximize your peak potential, but ultimate peak height is largely genetic (insertion points and muscle belly length).
The Bottom Line
The biceps has two heads—long (outer) and short (inner). Both work together during all curling movements, but you can emphasize one over the other through arm position. Include exercises that emphasize each head for complete bicep development.