First, if you're doing this exercise off the floor, load a barbell with a 45 - lb plate on both ends. (hardgainermusclebuilding.com)
Imagine this situation: you go to the gym, you are preparing for a heavy squat session, but there are not enough 45 lb plates in the gym. (fitnessandpower.com)
The bar itself weighted 45 lbs and it had two 55 lb plates loaded onto it. (fitnessandpower.com)