I do squats with like 450 lbs.
That sounds like so much weight! I do dumbbell squats holding a 45 pound dumbbell in each hand (age 55)). I do 15 reps (from standing to a point where the tops of my thighs are parallel to the ground), and 90 pounds seems like a lot. I feel like if they were any heavier, I'd risk pulling a muscle in my back when getting them off the floor. How many reps do you do?
So how is it that you are using over
four times as much weight as I. Am I that much of a weenie?