for example I plan to lift 300lbs 3 sets 6 reps in deadlift
so I do 3 warmup sets: 1 set: 50% x 6 reps , 2 set: 70% x 3 reps , 3 set: 90% x 1 and then rest and 3 work sets of 6
is that correct?
and as for bench press 200lbs , two warmup sets:
1 set: 50% x 6 reps , 2 set 80% x 3 reps and then 3 work sets of 6
correct?
Its a warmup. Unless you are competing in a meet, I wouldn’t over think it. I also wouldn’t start as high as 50%. I always start with foamrolling, then some shoulder prehab or mobility exercises, then a few sets with just the barbell.
do whatever it takes for you to feel “warmed up”
simple as that
however if im being a little more constructive i´d say starting at 50% is too high and ending at 90% is too close to your work set.
There is no correct answer. For example on Military Press I warmed up at 20lb intervals and hit a personal best. The next shoulder session I warmed up at roughly 50lb intervals. I didnt perform as well with 50lb increments. Go experiment and you’ll find your answer.
If you not sure how to warm up maybe you should be posting in the beginners section.