Stand beside a Smith machine bar with feet hip-width apart and hinge forward at the hips with a flat back. Grip the bar with one hand and pull it toward your torso, squeezing your shoulder blades together at the top of the movement. Lower the bar under control and repeat. Focus on a strong back contraction and steady core engagement throughout the set.
Log your smith single arm bent over row sets in 1RM.fit and watch your estimated 1RM update automatically as you get stronger.