Instructions:

1. Sit on a bench in front of a Smith machine with your feet flat on the ground.
2. Grasp the barbell with an underhand grip, hands shoulder-width apart.
3. Rest your forearms on your thighs, allowing your wrists to hang off.
4. Slowly curl your wrists upward, bringing the barbell towards your forearms.
5. Pause for a moment at the top, then slowly lower the barbell back down to the starting position.
6. Repeat for the desired number of repetitions.