Ahhhhhhh the topic of assistance work in powerlifting. This topic gets far more talk time than it should in the grand scheme of things. Assistance work does matter, but far too many guys get wrapped up in all the X's and O's of their assistance work and then wonder why their big lifts are moving as well as they would like. So I am going to cover my philosophy, if you will, about picking assistance work.
Adaptation specific -
My buddy Ed Koo and I were talking a few weeks ago about how specific the body is with moving big weights. His longtime training partner is an older fellow who pulls over 600 like the sun sets and rises. Ed said he quit pulling for a few months and was able to increase all of his other exercises for hamstrings, upper, and lower back. When he came back to deadlifting he went to pull 605 and it was STAPLED. I would expect it to be. For every guy that says he gained on the "no deadlift" program I will show you hundreds of other guys who lost strength that way. The "don't deadlift to increase your deadlift" may work for guys with perfect leverages to pull, but for the majority it's about as backwards as a philosophy as you can get.
Don't do something to get good at it? I'm not sure how that ever made sense to anyone. Ed's training partner got stronger in all of the musculature areas involved in pulling, but his actual pull went into the gutter. I experienced this same thing when I tried focusing on good mornings and box squats to increase my pull. I hit PR's in both the good morning and box squat and did speed pulls on a different day. When I went to pull heavy, weights I had previously moved easily, were ridiculously hard or stapled to the floor.
Get good at a lift by doing that lift. Especially if you aren't good at it. If you want to pick an assistance lift for that lift, pick one that mimics that lift very closely. You also must remember that you need to keep doing the main lift, even if the assistance work has great carryover. This is because of motor function. I believe that you can indeed train the main lift with lower percentages and push an assistance lift in weight that gives you good carryover. I intend to do this with my bench press for the upcoming meet.
Benching heavy every other week has worked well for me, however I believe that benching every week, but lighter, and pushing my incline hard will yield good results. My incline shot up using this method to right around 400 pounds and all I was doing was hitting 225-250 for a few sets of 15 after my heavy singles on bench. I believe this method will work for my bench as well, and not beat up my shoulders and elbows. Leaving me fresh.
So remember to train movement patterns, not muscle groups. Training the muscles involved in a lift doesn't mean that lift will go up. Performing the lift itself is the most important part.
Figuring out "weaknesses" and what to pick -
If there is any single "term" out there about assistance work that makes me chuckle it's when the "find your weakness" chant. Look, let's get real. The MAJORITY of guys have enough trouble setting up a program and following it. They have no idea how to "train weaknesses" and second, I'm not sure that's how it works anyway. I beat my hamstrings to death for years and was left with a deadlift that wouldn't budge no matter how strong they got. It wasn't until I stopped that shit and just started pulling heavy from the floor and from boxes that it started moving. According to some people, getting my hamstrings strong was the real key. Maybe it was, but the deadlift as it turns out, builds the hamstrings better than just about everything else. So I actually used the deadlift and a couple of variations of it, to build my deadlift. CRAZY I KNOW RIGHT?! /sarcasm
In my experience, finding the right assistance exercises just comes from trial and error. Lots of guys have been told to build their triceps to get a big bench and then spend all day doing pushdowns and skull crushers and their bench doesn't move. If simply building big, strong triceps were the key I promise you that everyone would have a big bench. I've never met a guy that didn't put considerable time into training his triceps.
So this is my own personal theory. You can take it, or give it right back (AnchorMan reference right there). Add in ONE assistance movement to supplement your main movement (do it after your main lift). Give it 4 weeks and push it hard in the 5-8 rep range. If it's a bodyweight movement, then shoot for a certain number of reps or do both (a top set of 5-8 followed by getting bodyweight for a certain number of reps).
You should improve in strength on it. If you main lift improves, it is helping. If it does not, drop it and try something else. Don't beat your head against a wall because someone told you that you have to do a particular exercise. Sometimes an assistance movement is building a weakness, thus improving your main lift, and sometimes it is improving your "strengths", and also improving the main lift.
Let's cut through the bullshit here. The bottom line is improving your main lift. Sometimes taking what you are good at and making that better is just as good as improving a "weakness". Throw out the "train your weaknesses" mantra and worry about what is helping the lift instead. Then you can cut through doing a lot of bullshit and figure out exactly what is working for you.
So if you are improving on strength in the assistance lift AND the main lift, then credit the assistance lift, and ride it out until the main lift stops moving. If the assistance lift is moving up and the main lift is not, drop it. Again, focus on the real key, improving the main lift.
When the main lift stops moving try something else as your assistance work and repeat the above.
Assistance for the Squat -
For me, the squat itself is enough. I have done every leg exercise in the history of lifting (or at least I think I have) and just squatting has always worked the best for me. I will give some variations I think have good carryover, but I honestly believe of the three powerlifts the squat is the one that requires the least amount of assistance work.
Pause Squats -
In my opinion pause squats are probably the single best assistance exercise a raw guy can do. Remember when you aren't wearing equipment you need to train the bottom portion of the movements. And with pause squats you will build a lot of strength coming out of the hole. I ran 6+ weeks of pause squats only and can say they will also grease your form like no other. Your sit down and core have to be super tight in order to move some "big" weights out of the hole. If you don't believe me try sitting down in the bottom then letting your breath out and watch what happens. This is a pretty interesting test. It will let you know right away how important it is to be tight in your midsection to move strongly out of the hole.
An easy way to put pause squats into your routine is to either just do pause squats for 5 sets of 3 (same weight) or to do them after regular squats. Take of 50-90 pounds of what you did for your top set of squats, then knock out 2-3 sets of 3-5. If you are running something like 5/3/1 you could use the first set plugged in for a percentage for pause squats and shoot for the required reps (so it would be 5,3,5 over three weeks).
Front Squats -
My feeling on front squats are fairly mixed. I think they do an awesome job of developing full body strength, maybe even more than the squat in some aspects, however as far as getting carryover to the actual back squat, I never got much out of them. Lots of people swear by then however so throw them in there and work hard on improving them and see what happens.
Box Squats -
For the raw guy, I believe box squats are incredibly overrated. Even on a below parallel box. When you sit down on a box and unload that bottom portion it creates an environment that is the opposite of what a raw guy needs. I've addressed this movement before in my article about raw squatting so I won't go into it again. I think that box squatting has turned into what HIT turned into in the 90's with guys training once every three weeks. Box squats aren't Gods gift to great squatting. It is a great tool for teaching beginners how to squat and in my opinion great for multi-ply guys, however for raw guys I don't think it is a good assistance movement. That's just from my own training and talking to a lot of other raw guys.
If you do want to do them, what I suggest is just TOUCHING the box then exploding up. This way you're not unloading the quads and hams at the bottom. Again, as with anything, work them in, give them a fair chance and figure out if they work for you.
Hack Squats -
Hacks are interesting in that you are in a fixed movement yet the quads work harder than they do in a regular squat. I am fairly intrigued about inserting hacks as an assistance movement for my squats for my meet prep. This may happen. If so I will document it here.
Zercher squats -
More worthless than rubber lips on a woodpecker for powerlifting in my own opinion. Great for strongman training. Again, try em out and see what happens. Yuck.
Leg Press -
Uh oh I brought up the leg press! This violates my "similar movement pattern" rule. However lots of guys have used the leg press as a good movement to aid their squat. Andy Bolton, Steve Goggins, Eric Lilliebridge, etc. I used to love leg pressing but once I got to where I could do 10 plates per side for high reps it just became exhausting to load all of those plates on and off. Some guys really like the 1-legged version for this reason better. Try em out and see what you think.
Bench Press -
Grip variations -
This is probably the best overall way to work on increasing your raw bench in my opinion. You can do your competition grip work, then do some close grip and then wide grip stuff. This was really common back in the 70's and 80's before the shirts got crazy.
I have fallen in love with incline as a bench builder. No it's not in the same plane but I can move pretty decent weight on incline, and for whatever reason it has great carryover to my bench. Remember, I define carryover as "the assistance lift goes up and the main lift goes up in conjunction". In regards to incline and bench when one goes up the other one does as well. Now I don't mean to say I could do incline only and increase my bench. I still have to actually bench.
Dumbbell bench -
A lot of guys like dumbbell bench to aid their bench. I like dumbbell benches for rep work but never noticed they made my bench feel better. I do think they have a lot of merit, I just don't know why. HAH!
Cambered Bar Bench -
This was a favorite of the great bencher Mike MacDonald. Be careful if you use these. You don't have to bring the bar down to touch actually, just bring it slightly below the usual ROM for bench. Again, be careful on these because they can be rough on the shoulders.
Box Deads of various heights -
What I call box deadlifts is when you put the weight on the box, not standing on the box (I call that deficit deadlifts). I also only advocate pulling off the box from below the knee. I did above the knee for a long time and never found any carryover to the floor. Again, your mileage may vary so try each out. I will say that when you pull from below the knee you will find spots where you are weaker than you are from the floor. TRAIN THAT AREA!!!! It will suck but it will help your deadlift tremendously.
Deficit Deadlifts -
If you do these mind the height of what you are standing on. If you get too high you can get more quad involvement and it kind of becomes a whole new lift. I find that is the case for me anyway, and then when you go back to the floor there isn't as much carryover. Try smaller deficits at first, like standing on a single plate.
Stiff Legs and Romanians -
I did well with these too. Pulling stiff legs for high reps works pretty well because you stay a little lighter.
Like I said, throw in one assistance movement at a time and work it hard for a few weeks. As it improves make notes of what is going on with your main lift. If it doesn't improve in some fashion, drop the assistance movement. And once again, remember that like all good things it must come to an end. In the end it is all about improving the main lift, so judge the worth of your assistance work based on what is happening with your main movement. Not the other way around.