Anyone else have a problem keeping your squat form in check after the first few sets of squats? Today I did a 5x5 workout of squats using 280 lbs and the first 2-3 sets were good. On the fourth set the first few reps are good and then it starts to feel as if the weight is getting heavier and heavier and on the way up on the last 2 or so reps my back starts to come forward and it becomes a good morning squat. Do you guys think I should invest in a weight vest to use once my core becomes unable to support the load I am squatting? Because I feel if I were doing a 1 rep max I would have plenty enough core strength to squat it in good form it's just after these multiple sets with relatively heavy weight that I can't keep my back straight on the way up.