here is the rule and a lot of you won't follow it because of ego. but you should warm up with just the bar. then gradually increase the weight. don't just throw on 1 or 2 plates and go. that is a great way to tear a muscle or tear your rotator cuff. i tore my rotator cuff because i would throw on 1 plate on each side and do a little warmup, then throw on 2 plates and then jump to like 275 right away. you can't lift with a cold joint or muscle