21s Bicep Curl (Barbell)

A barbell biceps curl protocol using a 7-7-7 rep scheme to maximise time under tension. Seven partial reps in the lower half, seven in the upper half, and seven full-range reps for 21 total reps per set.

Instructions

1. Stand holding a barbell with a shoulder-width underhand (supinated) grip, arms fully extended.
2. Perform 7 partial reps from full extension to the halfway point (approximately 90-degree elbow angle), keeping the upper arms stationary.
3. Without resting, perform 7 partial reps from the halfway point to full contraction at the top, squeezing the biceps at peak.
4. Without resting, perform 7 full range-of-motion reps from full extension to full contraction.
5. Lower the bar under control and repeat for the desired number of sets.

Tips

• Use a lighter load than your standard barbell curl — the extended time under tension makes this significantly harder.
• Keep your elbows pinned to your sides throughout all three phases; avoid letting them drift forward.
• Control the eccentric (lowering) portion of every rep, especially during the full-range phase.
• The halfway point is defined by a 90-degree elbow angle — forearm parallel to the floor.
• Avoid swinging or using momentum; if you need to cheat, the weight is too heavy.
• This protocol is the barbell variant of the 21s technique; the dumbbell version allows independent arm work but the barbell provides a fixed path and higher load potential.