Marcus gives good insight. Learn to do any exercise the correct way to reap the rewards. Set the Ego aside and start with a lighter weight for awhile. Also experiment with different grip and elbow positions for different effects on the back with the BB row.
You are not going to isolate the lat's, or any other muscle group, that is misleading thinking. A BB, machine, cables, etc will not do that. But a compound (two joint exercise) movement, like BB rows, can give a better opportunity for muscle mass. If someone has a fear of exhausting exercises, that produce max results, than they are missing out on a lot of positive returns (we do not want anyone to fall over in a faint when faced with attempting to use heavy compound exercises. That is, if the goal is reaching their full muscle potential. Better for them to go back to their foo-foo light fitness machine exercises).
Along with BB rows, the squat, Dl's, heavy benches, etc fall into the category of prime mass/strength builders. And are the core exercises for most successful BB'ers. Might try the curl grip (medium hand spacing) when doing BB rows for better recruitment of the lat's themselves. A wider grip (elbows out) and pull to the mid chest affect the posterior delt and lower/mid traps better. But of course, this never will take the lat's out of the exercise.
If done the correct way, the BB rows will strengthen the lower back area greatly, giving thickness of muscle around the spinal area. Also affect the ham's. Good Luck.
