Standing

1. Stand erect holding a dumbbell in each hand, with arms hanging straight down, palms rotated in toward the thighs, and feet shoulder-width apart.
2. Keep the abs tight and the back straight, and avoid swinging the body throughout the movement.
3. Inhale, supinate the palms (turn them up) and curl the dumbbells up toward the chest until the elbows are completely bent.
4. Squeeze the biceps muscles at the top, exhale, and lower the dumbbells back down to the starting position.
5. To do this exercise with alternating arms, fully complete the movement with one arm and then complete the movement with the other.