Dumbbell Underhand Bent-Over Rows target the lats (latissimus dorsi), rhomboids (upper back muscles), and biceps (arm muscles). Hold a dumbbell in each hand with an underhand (supinated) grip, hinge at your hips, and keep your back straight. Pull the dumbbells toward your lower chest or upper abdomen, then slowly lower them to the starting position. This exercise strengthens the upper and middle back, enhances bicep engagement, and improves posture and overall upper-body definition.