Out of curiosity, what's the problem with deadlifting or squatting in a fatigued state, as long as technique is good? I'd say that load used on the second lift is definitely going to be lower than it would be if that lift was first but - kinda obvious, really - however as your work capacity increases it'll go up, even in a fatigued state. I would also say doing any of the big lifts in a fatigued state isn't for beginners. Technique
I don't see much merit in using Competition Deadlift as a training exercise. Nor do I see using a Competition Squat or Bench Press as a training exercise.
I am a proponent of peforming the competition movements with heavy singles with load of 85% of 1RM (Repetition Max).
"Pole Valuting For Reps"
The irony is that powerlifting is the only sport that I can think of that used the competition lifts as training exercises.
You don't see pole valuters pole vaulting for 5-10 repetitions.
That is one of the biggest points that Dr Tom McLaughlin (PhD in biomechanics and former powerlifter) made Bench Press More Now.
This group is more akin to powerlifters. They perform mostly single reps with high loads.
In other words, they perform the lifts for technique. They don't use the competition lifts as trainng exercises.
Olympic lifters use auxiliary exercises to strengthen the competition lifts...squats, deadlifts, presses, etc.
Simmons borrowed the same philosophy from Olympic lifters. Utilize auxiliary exercises to strengthen the powerlifts.
I'd say the once fatigue sets in, even an elite athlete need to STOP.
I've done a couple of squat variations in one workout, or a squat followed by DL variation in one work out for years now. It's not often i've done squats after a DL variation but i've done the opposite many times. I've done things like Box Squats then Rack pulls.
Squat Prior To Deadlifts
If you going to perform them in the same training session, this is the most logical approach.
Also, I've just recently finished following an 8-week program, focusing on deadlift, written by Josh Bryant (impressive background as a coach and a Powerlifter). I should mention I decided to do it because I didn't like the look of it and couldn't see where he was going with it. I couldn't believe how much fatigue it caused in the lower back. Josh Bryant
Bryant is one of the smarter guys in the game. Overall, I am impressed with his knowledge.
Bryant, as I, am a proponent of performing plyometrics as a means of increasing your powerlifts. He wrote a good article on it about a decade ago.
It had 3 deadlift variations in a row, the third variation being 3-inch deficit DL's (the "assistance" included bent over rows, shrugs, and GHR's). Day 2 had box squats followed by "dead" quarter squats, followed by front squats - I reckon your lower back doesn't know the difference between a box squat and a dead lift, in terms of stress. Anyway, in the first week, my lower back was so fatigued that I had to lay on a bench with my feet up between sets to let it drain. I instantly questioned whether I was conditioned enough to keep doing it (it was my first deadlift intense training since coming back from a hamstring tear). It was then I understood why the program started with such low percentages of your 1RM. However as the weeks went on I felt nothing in my lower back. It adapted quite significantly by just the second week. Granted, it's lost strength that i'm regaining (although i'm about 20lbs lighter), I put 15KG on my deadlift in 8 weeks.Low and High Volume Training
There appear to be two types of individuals. Those who respond well to low volume and others who respond to higher volume work.
So, what works for one doesn't necessarily work for the other.
A case in point is Olympic lifter Casey Burgner. As per his father (Olympic lifting Coach Mike Burgner), Casey responds better to low volume training.
When Casey moved to the Olympic weightlifting camp in Colorado Springs, they put Casey on a high volume program. Casey's lifts dropped.
It got me thinking about GPP, or, "work capacity", or whatever you want to call it. This definitely improved A LOT with me during that 8 weeks (I was actually physically sick after day 1 of week 1). Also, we all know the lower back can be a limiting factor in both squats and deadlifts so, why shy away from trying to both strengthen AND condition it?GPP
GPP is another one of those things that make my head spin around 360 degrees and while speaking in tongues...just like in the movie the Exorcist.
GPP is overrated.
GPP does help to some extent with recovery. However, Non-Linear Periodization accomplished that while allowing you to become stronger.
I guess what i'm saying is, maybe the purpose, or one of the purposes, of doing the squats after deadlifts is to build conditioning in the lower back, or just conditioning in general. I think gpp/work capacity are probably quite overlooked when it comes to strength training. I "think", anyway....
Squats After Deadlifts for Back Conditioning
I don't see much value in using a leg exercise for back conditioning. A better back-posterior chain movement would be a kettlebell swing.
The kettlebell swing is much more effecitve in allowing you to pump blood into the area for recovery. Performing the kettlebell swing after your deadlift workout will promote recovery.
Taking Out The Garbage
Blood delivers nutritent and also "takes out the garbage". Thus, some type of pumping movement helps with recovery.
There isn't much value in using squats for lower back conditioning. The lower back for the most part performs an isometric action...maintaining you in an upright position.
The exception to the rule is when you perform one of Ken's "Squat-Mornings" in which you break parallel twice. Once at the hip joint and the other by bending low enough with your lower back so it breaks parallel with the floor.
Now that is a Back Conditioner!