Dumbbell Rotating Curls Single Arm target the biceps while engaging the forearm through rotation. Hold a dumbbell in one hand with your palm facing inward. As you curl the dumbbell toward your shoulder, rotate your wrist so the palm faces upward at the top of the movement, then lower slowly with control. This exercise builds arm strength, definition, and balanced development. Gymcheq emphasizes controlled motion and proper posture for safe, effective results.