Pfft what could those scientists/doctors/trainers/experienced athletes possibly know that some dude on the internet can't anecdote his way into correctness? /s

Engineer/trainer/experienced athlete here

I thought using the potential energy equation gave me a little credentials.

I also wrote a book about this topic. But I didnt include it in the comment.

Could you link to the book?

My point is, actually, that whenever someone says "I just do 1 set or 1 rep and am done, after warmup" that the warmup sets are really part of the exercise...

looks like mkirklions responded and really he does 5 sets with increasing weight, then does his heaviest.

So it is more like the classic "pyramid" or "increased weight until near-exhaustion" sets, which have been around since forever...

It depends on what percentage of his 1rm he's doing. I use 531 and it's based off a training max which is 90% of your 1rm. You never lift heavier than about 85% of your 1rm on the program because doing so is heavily taxing on your CNS. Unless he is using PEDs he probably won't last long-term if he's lifting close to his 1rm twice a week.

Especially with deadlift, back injuries are no fun at all.

Indeed.

Working up to a deadlift max doesn't take a lot of time, or a ton of sets. Like, 4-6 sets of 3-4 reps.

Longevity and injury-prevention is key to long-term gym vitality... but people don't usually appreciate this until they injure themselves somehow.

<40-something lifter, out...>

Seconding this.

1 heavy deadlift set usually means 15 minutes of warmups.

After doing strength training for years, it is all part of the routine.

You cannot do 5x5 deadlift sets once you are past 4 plates.

You can, but it's not a lot of fun. I did it for years as a modified BBB element in 5/3/1. I have, at various times done 5x5 squat past 4 plates as well. Didn't last more then 3 weeks before I had to back off, I'm too old to recover from that, but I was working Texas Method at 415 lbs, which was just as hard as it sounds.

Sure you can, it's just that progress goes much slower. When I finally got into the 500s I was counting 1/2 and 1/4 reps as progress. For example, if I got 525 for 3-1/4 reps for one workout, and later got 3-1/2 reps, that was progress. Keep in mind for me that later could be weeks or months as I'm not naturally big.