Body Mechanics & Muscle Recruitment: Sit on an upright bench with dumbbells at your sides, palms facing inward. Bring each dumbbell up alternately, actively rotating your wrists outward (supination) as you ascend to fully recruit the biceps long head for maximum peak height. Lower the weight deliberately back to full arm extension.
Tempo (3-1-1-1): 3 seconds eccentric return, 1 second stretch, 1 second alternating curl with wrist supination, 1 second top peak squeeze.
Rest: 75 seconds between defining sets.
"Delavier Note: Seated alternating dumbbell curls allow intense wrist supination at the apex, recruiting the outer bicep head for enhanced peak definition."