Stand with feet hip-width apart holding a dumbbell in each hand in front of your thighs. Keep a very slight bend in your knees and maintain a tall chest. Hinge at the hips by pushing them backward while lowering the dumbbells straight down along the front of your legs. Keep your back flat and the weights close to your body throughout the movement. Lower until you feel a strong stretch in your hamstrings (usually around mid-shin or slightly lower depending on flexibility). Avoid bending your knees further as you descend. Drive your hips forward, squeeze your glutes, and return to a standing position in a controlled motion. Repeat for the desired reps.
Log your dumbbell single stiff leg deadlift sets in 1RM.fit and watch your estimated 1RM update automatically as you get stronger.