You mentioned slowing the pace of the rep. For me, in the case of today, doing dips and chins the pace automatically slowed on the last few inches of the ROM and was a down right struggle. I didn't have to change the pace. This told me I was done. Basically got 3/4s of the way thru the rep then it was "uh oh" and squeaked out the last 1/4 kind of thing.
This is true. When the rep begins to slow down, it's the beginning of the end. However, I'm occasionally able to get in one more decent rep, as I'm sure you are as well. It's a judgment call, I suppose, depending on where in the rep the pace begins to drag. As an aside, I know that true HITers use a very slow rep speed throughout the set, but that never appealed to me. I prefer a more "natural," deliberate pace that's uniform and fluid enough to ensure that I never rely on kipping or momentum of any kind.
I think 8 sets of any exercise is "insane," especially if you are going for intensity. But, yes, deadlifts would certainly be at the top of that list.
I hear ya. I'll usually finish the rep, let's say on chins. Squeeze it out at the top, descend into the eccentric and at the bottom is the decision point. Most times my brain just says no almost like it turns off. Does make me wonder if my muscles do have a little more juice in them as sometimes I do feel like my mind fails first in a way. As far as the deliberate pace, I worked at a facility where the client had to perform each rep for 10 seconds. 4 second concentric, 6 second eccentric. Most couldn't keep that tempo nor reach failure. But I agree with you regarding a more natural pace. Not to bring up the term functional strength, but no where in life would you put down and pick up boxes on and off the floor taking 6 seconds to bend down and 4 seconds to lift it up off the floor.
Something occurred to me. (Out of boredom as we approach the noon hour, I suppose.) Even the people who encourage training to momentary muscle failure stress the importance of maintaining proper exercise form. However, I have noted that form typically begins to degrade a bit even by the last full repetition. Assuming that this is a common phenomenon and not limited to my own experience, would that not theoretically invalidate the argument for attempting the next rep, which would not be completed in its entirety, i.e., true momentary muscle failure?
I guess it depends on what one considers proper form. There are even different views on proper form. I'd say my form doesn't degrade, just the inability to perform a rep gets more difficult as the time under tension increases and the pace of the reps generally slows, however I don't suddenly start swing or arching/putting myself in a bad position to complete the rep. If you have to "cheat" to complete the reps then yes, I'd say stop/you failed within proper parameters. That's why attempting to keep a relatively consistent tempo is important also. Easier to catch myself cheating.
One notable example in my case is with pull ups. I keep my body straight and my knees bent at a 90-degree angle. However, by the last rep, I notice my knees moving forward (a slight bending at the hips), not to create momentum, but just to allow me to get to the top of the bar. I don't jerk or kip, but this change in position is my marker for last ~good rep. In the case of dips, there is not as obvious a sign, but the pace does slow down and becomes a bit of a grind on the last rep. So I must agree with you on speed as a marker. However, depending on the weight I'm using, and where I am on the last rep, my elbows may have a slight inclination to flare out a bit to complete the rep. That is always an indication of "last call." With the pull ups, however, the slight raising of the knees happens at the end regardless of the weight I employ. Also, with the pushing exercises, I notice that I slightly wobble/shake at the last good rep if I just barely make it.
I do the same if I'm at home since I have to bend my knees in order for them not to hit the ground since I train in my basement. If at the gym though I don't bend my knees so that hip hinge doesn't happen at all. It's feet together, butt tight, belly pulled in, essentially trying to be stiff as a board. However w that said the whole angle of my body does shit in that position as I reach that "failure" point. I guess that's similar to hip flexion.
In my case, I find that bending the knees at a 90-degree angle (with hips straight) for pull ups helps keep the movement entirely vertical, with absolutely no forward/backward sway. I see other people at the gym doing them with their knees straight and, perhaps due to their inexperience more than knee positioning, they tend to sway back and forth a bit during the movement. For me, anyway, the knee bend keeps all sway away. I feel more in control.