Stand or sit tall, dumbbell each hand, arms extended, palms facing thighs (neutral) or forward (supinated).

Keep elbows tucked.

Curl one dumbbell (e.g., right) towards shoulder. Supinate wrist (turn palm up) during curl if starting neutral.

Keep upper arm stationary.

Squeeze bicep at top.

Slowly lower dumbbell.

Repeat with other arm (left). Continue alternating.