Originally Posted by
Dillon Spencer
You're right that the "bring your chest up" step is the weakest link here. Really focus on getting your nipples pointed at the wall in front of you. At this weight you may even feel the bar start to break the floor if you're squeezing up hard enough. Are you able to arch your lower back when just standing? Seems like a silly question, but lots of people can't.
You're also lowering the bar around your knees on the way back down, causing the bar to creep forward of mid foot throughout the set. To lower it, stick your butt back until the bar passes your knees, then break at the knees to get it the rest of the way to the floor.
Also, if you're doing 5x5 on deadlifts, be prepared to stall out sooner than later. Around here the program calls for 1 set of 5 on deadlifts for novices because they get very strenuous very quickly.