Hello!I hold one dumbbell in one hand only because of stability,if I use two dumbbells in each hand, it is harder for me to stay stable and I can’t focusthat well on my muscle I am working on, if you are stable,then you can use two dumbbells if you want, this is a matter of a choiceBack exercises, deadlilft,back raises,pullups,row etcregardsl.O |