You do need some weight on the bar, just squeezing up with 45lbs isn't going to do dick but slow reps with a pause and a squeeze are a great way not to get hurt lifting compared to heaving heavier loads around.
Obviously drug intake governs the amount of muscle you can hold and how 'strong' you are more than training. Anyone can binge eat for a few months and run a huge cycle and add 100's of lbs to their 'big 3'