Tweakle said:
Unless your form is drilled in for every rep then you'll likely lose your leverage, raise your hips too fast if your try to pull fast from the start and actually make the rep harder (plus you'll increase your chance of getting hurt if you get out of the groove)
Build up speed when the bar is moving imo
This is a good point, and I have to admitt, it is a point I failed to address. I was thinking more in terms of executing one rep.....but this is correct, and is also what I meant when I said don't be sloppy or jerky, don't jam the bar off the floor or bend the elbows, don't bounce it off the floor between reps either, etc....when I say lift fast, I tend to take these points for granted.
Deadlift form is a topic of debate. Honestly, when I go all out and hit heavy singles, doubles, or triples, my form isn't textbook perfect, maybe close a lot of times, but there are minor breakdowns.....some guys are 700-800lb deadlifters and they do so with a rounded back, in my opinion this is okay if they understand their body, have a strong core, and understand their individual leverages. Sometimes when repping deadlifts for a max number of reps (say, in a strongman contest), the form naturally breaks, an advanced lifter can better manage fatigue and understand how to stay injury free more so than a beginner who never learned how to pull textbook to begin with. If your interest is bodybuilding, you'd probably want to keep a little more textbook form. A lot of world-class powerlifters break down a little with heavy attempts, a good deal of them don't break down at all with big singles, this always stirs up debate, someone will point out an 800 pul with a rounded back, someone will counter with an 800 pull executed to perfection, if you ask me , at that level a pull is a pull. It is an individual thing, but a beginner should learn how to pull textbook at first. I think if you sweat every little form detail, you'll never really laod the bar up. A lot of high school coaches won't let the kids DL because of common form breakdowns being coupled with the teenage ego leading to many injuries.
As far as rounding the back. I do not encourage it, and I would never 'teach' somebody learning to pull to do this, however, I have seen enough 700 plus pound pulls with a rounded back to know better than to bash it. Hell, I have straight-leg deadlifted pretty close to my conventional pull with no problems.....a lot of it comes down to not being jerky and having a strong core. This, of course, is a strength training perspective. From a hypertrophy and teaching perspective, I have to say lift as close to perfect form as you can.....what I do and what many others do is not what a beginner or a guy looking to just build some size should do.......sometimes you have a situation of "do as I say, not as I do"......but I hope my honesty helped a little, and there are two sides to this....sometimes how you teach and what an advanced lifter does to keep advancing.
Thanks for the post Tweakle, because I wasn't even going to bother going into that, but I think it is important, and you do raise an EXCELLENT issue.