An excellent exercise to develop your biceps.
Sit. Your back, head, shoulders, and butt make contact with the bench. Grasp a dumbbell in each hand with your arms at your sides, close to your body and your palms are facing forward. Pull the shoulder blades down and back.
Exhale and slowly bend your elbows bringing the dumbbells toward your shoulders. Do not allow your back to arch, your shoulders to shrug, or your elbows to move forward. Keep the wrists in line with your forearms. Do not allow the wrists to bend throughout the exercise.
Inhale, straight your elbows and lower the dumbbells back to your start position and repeat.