Triceps
Three heads, and the largest one is trained badly by the exercise most people do most.
2 min read
Function
Triceps brachii has three heads — long, lateral, medial — all converging on a shared job: elbow extension. The long head is the one to know in detail, because it is the largest of the three and the only one that crosses the shoulder as well as the elbow.
Origin and insertion
The long head originates at the infraglenoid tubercle, just below the shoulder socket — a shoulder-crossing origin, same pattern as biceps' long head. Lateral and medial heads originate lower on the humerus itself, crossing only the elbow. All three insert together at the olecranon process of the ulna, the point of the elbow.
The pushdown problem
Because the long head crosses the shoulder, it is only meaningfully stretched when the arm is overhead. With the arm at your side — the position for a standard triceps pushdown — the long head is already in a shortened position at the shoulder end before the elbow movement even begins.
A pushdown trains the lateral and medial heads well. It trains the long head — the biggest of the three — comparatively poorly, because the exercise never puts it at a long length.
This is one of the clearest, most common gaps in commercial programming: pushdowns are the default triceps exercise almost everywhere, and the head they train worst is the one with the most mass to gain.
The fix is any overhead extension — cable, dumbbell, or barbell, with the elbow pointed at the ceiling. That position stretches the long head at the shoulder simultaneously with the elbow-driven stretch, which a pushdown cannot replicate regardless of load or reps.
Exercise selection
| Exercise | Head bias | Position |
|---|---|---|
| Overhead cable/dumbbell extension | Long head | Arm overhead — the only common position that stretches it fully |
| Pushdown (rope or bar) | Lateral, medial | Arm at side — long head undertrained here |
| Skull crusher | Long head, moderately | Arm overhead-ish depending on bench angle |
| Dip, close-grip press | All three, moderately | Compound — useful but not a substitute for direct overhead work |
A program using only pushdowns for triceps is training two of three heads. This is the single most common and most easily fixed gap in the exercise selections of programs that do not reason from anatomy.
Source tier: the shoulder-crossing anatomy of the long head is uncontested. The overhead-position argument follows directly and is one of the better-evidenced resistance-profile claims in strength training — not a contested or minority position.
Up next
Calves
Two muscles, one straight-leg and one bent-leg, and most people only train one of them.
2 min