There is no need to go too heavy with face pulls,” says Sprague. “Your focus should be on stretching and contracting the muscles with control throughout.” If you’ve gone too heavy you’ll probably be drawing on momentum and swaying into each rep, which can increase the strain on your lower back and take the tension off your rear delts.
The Fix: “Start as light as possible and see whether you can control the movement,” says Alexander. “If you can get 15 reps with that weight, without swaying or using momentum, then you can go up.