At seminars I explain what to do to get your lifts to come up. Most attendees understand, make corrections, then set new records. If you know the path the bar is supposed to travel in any lift, then it's easy to see if the problem is technical or physical. Once you realize this, the solution isn't that hard to find, and your lifts should go up.
But there's always the occasional dick who totally disagrees with everything I say. And sometimes it's not a lack of understanding, but an abundance of ego he's using to wrap around his physical limitations. These guys fall into one of two categories.
Category A: The Put-On-Some-Weight Guys
I can't relate to these twerps who want to get super strong but refuse to gain weight. These guys have little or no muscular development, they're around six-foot-one and weigh 135 soaking wet. You can see their collar bones sticking out from a mile away, and their elbows can be used as weapons.
I have no idea what their problem is. They have no muscle to begin with and are terrified of losing their abs. To add muscle, you have to take in a few more calories than you burn off. Yes, you can gain muscle and lose fat, but the people who do this already have some muscle to begin with: a fat-loss "engine."
If you fall into this category, please understand that when I tell you to gain weight I'm not saying to increase your body fat to 20%. All I'm saying is that if you're looking to add size and gain strength, 10-14% is going to be a lot better for you than 4%.
Category B: The Get-in-Shape Guys
You can spot these oafs a mile away. They show up wearing high top Chucks, a shirt that says Go Heavy or Go Home, a shaved head or beard, and what I call proportionate fat. Hey, I'm all for filling out your weight class, but it's a huge mistake to fill out four weight classes over the muscle you hold on your frame. Certainly not at the expense of your conditioning and recovery.
Seriously, folks, you can weigh whatever you damn well please, but if you can't walk 100 yards without stopping to catch your breath, then you really need to get your fat ass into shape. If you're in this poor of shape your body won't be as efficient at processing nutrients, thus impeding recovery and gains.
Now, don't misunderstand me. I'm not saying you need to be a marathoner, but I've seen a shitload of lifters who are in such bad shape I have no idea how they even make it through a squat session let alone a meet. If you happen to be one of these guys, you might want to think about getting a sled, or maybe walking every now and then.
Of course, if given the choice, I'd always take a guy from group B over group A. It's much easier to teach a guy who already has some underlying muscle to eat clean, than to try to convince some bean pole that it's okay if his abs disappear for a while.