Instructions:

1. Stand with your feet shoulder-width apart and hold a barbell with an underhand grip, hands wider than shoulder-width apart.
2. Keep your back straight and your elbows close to your torso.
3. Exhale and curl the barbell up towards your shoulders, keeping your upper arms stationary.
4. Pause for a moment at the top, squeezing your biceps.
5. Inhale and slowly lower the barbell back to the starting position, fully extending your arms.
6. Repeat for the desired number of repetitions.