Muscle: Biceps Brachii
Step 1: Attach a straight bar to the low pulley of a cable station. Then, grab the bar with a shoulder-width, underhand grip and hold it at arm's length just in front of your thighs. Try standing straight with your upper arms tucked against your sides and your feet hip-width apart. Your knees should be bent slightly.
Step 2: Curl the bar toward your chest as far as you can without allowing your upper to move.
Step 3: Pause, then slowly return to the starting position.