We are a commune of inquiring, skeptical, politically centrist, capitalist, anglophile, traditionalist New England Yankee humans, humanoids, and animals with many interests beyond and above politics. Each of us has had a high-school education (or GED), but all had ADD so didn't pay attention very well, especially the dogs. Each one of us does "try my best to be just like I am," and none of us enjoys working for others, including for Maggie, from whom we receive neither a nickel nor a dime. Freedom from nags, cranks, government, do-gooders, control-freaks and idiots is all that we ask for.
Whether you are doing an hour of weights, calis, or HIIT cardio, I think most of us ordinary exercisers reach the point in a given effort when something says "OK, I'm done," but a better voice says (in my case) "Don't be a pussy - push through and do more." I find that self-insults work well for me, as do either insults or encouragement from others.
Distance runners talk about hitting "the wall," but persisting through the wall and finding more energy on the other side. These experiences are both mental and physiological, having to do with the energy sources your muscles or your heart are using and the amount of power your body can enlist.
Yesterday I did elliptical semi-HIIT, semi-long slow on the elliptical (because Wimbledon) on TV. When I do this on elliptical (always using arms too to make it full-body) I do 30-second sprints with 60-second slows, or for variety, I will keep a steady RPM pace while upping the resistance from 1 to 10, increasing every minute and then dropping back down the same way.
After 35 minutes of low-resistance 30-second sprints, I was done. Or thought I was. I called myself a wimp, took a minute slow on level 1, and then got right back in the game to complete the hour going up and down the resistance levels. I have similar experiences in my calis classes.
On the other hand, we all have real limits and it is amusing and educational to confront them in regular life and in physical exertion. Well, depressing too. All we have to do is to check whether it is a real limit or a mental determination speed bump.
On my 5th set of deads this morning (increasing weight and decreasing reps for each set) I found I could not get 3 reps at 245. Genius trainer said "Quick, reset your grip and go again." I think I engaged all my will and force but the goddam thing felt glued to the floor. With a minute's rest, I could have done the third, but that's not the way it works. For you strong guys and gals, this would not be too difficult but I am not you. A fit, skinny, no-bulk gal I know does 3 reps of 300. She is only 35, though.
I think it was a true physical limit at that point in my dead routine, because I engage everything so as not to disappoint my trainer's expectations and demands. However, for that moment, I am fairly confident that I was done. Sucks to disappoint a mentor.
When I think about it, I most frequently encounter genuine limits in jump rope and in pull-ups. Also, the sprints on the combat bike. Even the f-word just doesn't help at all.
I wonder how our readers feel when things go from manageable to tough to hard to painful to walls to breakthoughs to actually confronting real limitations.
You know that, I know that, my knees seem pretty ignorant.
As I start over I do much less weight and work on form. But at some point in t a lift my knees go from almost straight to bent at 90 degrees and back with something like 250 lbs of pressure on each knee during a heavy lift.
Well, then, I submit that you need to work on proper form. When a squat is done properly, the force on your knee is balanced by the tension applied by the hamstring (pulling from the front) and quads (pulling from the back). See https://startingstrength.com/article/squats-and-your-knees for a more in-depth explanation.
I’m curious about why you wouldn’t rest another minute (or even 4 or 5) in order to get that last set of deads. Presumably this is a strength build day, not and endurance building day, so I would think spending 3 - 5 minutes letting your muscles replenish themselves is the way to go.
But if strength is your goal, those four previous sets didn't contribute to strength-building because they were too light to effect a change. Only the top work set builds strength. In this case the four sets just tired you out and kept you from lifting the heaviest weight and building strength. For a top set of 245, I would do something like 135 x 3 (or 5, depending on how warm you are from previous exercises), 185 x 2, 225 x 1, 245 x 5. The lighter sets are just for warm up and to practice the deadlift motion and for deadlifts, one work set is enough. What was your weight x rep scheme?