7. Bent-over lat row
The faux pas Rounding your spine and not flexing from your hips, pulling the weights up too far behind you
The facts These mistakes place stress on your spine and reduce the demand on your back muscles, making the move less effective.

The fix Stand with feet hip-width apart and hold a dumbbell in each hand, arms by sides. Bend knees and flex forward from hips at about 90 degrees. Let arms hang in line with shoulders, palms facing in. Contract abs to support back. Draw shoulder blades down and together; maintaining body position, bend elbows up and in toward waist until upper arms are in line with torso and forearms are perpendicular to ground, knuckles pointing down (shown). Slowly straighten arms to starting position without changing torso position. Strengthens middle back, rear shoulders and biceps.