Another factor that I believe helps determine how much weight you can pull is what stance you use. Some guys use the conventional stance where you stand with your legs close together. The Sumo stance (which is what I prefer) is where you use a wide stance with your toes pointing out. Personally, it feels like I'm putting less stress on my lower back when I deadlift using a Sumo stance. But it's really boils down to personal preference. Experiment with both to see which one works best for you.
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