To perform a Single Leg Romanian Deadlift (RDL) with dumbbells, begin by holding a dumbbell in each hand with your arms by your sides. Shift your weight onto one leg and hinge forward at the hips, simultaneously extending your free leg straight behind you to create a T-shape with your body. Lower the dumbbells towards the ground while keeping your back straight and chest lifted, then return to the starting position by engaging your glutes and hamstrings.