These will challenge you more than any dumbbell row. You'll be essentially rowing your bodyweight with one arm.
Don't let your shoulder shrug up, keep your core braced, and pull with control. You'll feel your core work double-time to stabilize the offset load. Your pulling muscles will also contract deeply. To make it easier, simply go flat footed or adjust your angle.
Think you have what it takes to make it in the world of elite sports? Do you have immense talent and ability? Great, but so do a few thousand other guys. Unfortunately, all of these things will only get you so far in this world where good isn't often good enough. At this level you have to be one of the best just to get your foot in the door.