Levels to an exercise

 This post is meant to describe free weight bodybuilding exercises. Especially those done with dumbbells or barbells. However, maybe in theory, it can be used to describe other exercises as well. 

The 4 levels are Starter, Novice, Intermediate and Advanced, and within each of these there are sublevels as well. The highest sublevel of one class is the same as the lowest of the next class. 

Starter: The defining trait of the starter class is that they do not yet have the skill to do the exercise with good form in a way that is optimally conducive to hypertrophy and strength gain. Depending on the level, their form is either never good from the start, or breaks down when they start to feel fatigue. 

sublevel 1: A level one starter is unable to do the exercise with form that is safe to use with heavier weights even when there is virtually no load. 

sublevel 2: Level two starters are able to do the exercise proper form under light load, however, their form breaks down when significant load is introduced. 

sublevel 3: Able to use good form with significant load, but form breakdown long before failure. 

sublevel 4: Able to use good form until at or very close to failure with light weights above the 10 rep max. 

Sublevel 5: Able to use good form until at or very close to failure with weights heavy enough for a 5 rep max. 

Novice: The person is able to perform with good form even at heavier weights within the 1-5 rep max range, but their total strength gain is small enough that they adapt to heavier weight fast. 

Sublevel 1: Able to perform good form with weights within the 5 rep max, and upto no more then 1 rep short of failure. Can progress with single progression on barbell movements and double progression on dumbbell movements, setting PRs in the exercise at least once every 3 workouts. 

Sublevel 2: Single progression can be maintained with fractional plates, otherwise, double progression is needed for both barbell and dumbbell movements. 

Sublevel 3: Double progression is needed to progress in both barbell and dumbbell movements even when fractional plates are used. 

Intermediate: The person now can no longer gain additional strength quickly. But, they are still capable of gaining strength with relatively few movements. 

Sublevel 1: Triple progression now necessary to progress on dumbbell and barbells. Double progression might still be adequate for barbell progression when fractional plates are available 

Sublevel 2: Triple progression is needed for all movements. Either that, or double progression, but with differing weights for both heavy and light exercises. This is when drop-sets, heavy and light days, etc, become necessary. 

Sublevel 3: Both triple progression and load variation is necessary to progress in the exercise. Either that, or isolation of the weak links in the case of compound exercises may be needed. 

Advanced: The exercise is now very difficult, but not impossible, to progress. Progress may be very slow. 

Sublevel 1: Triple progression of varying loads is necessary. 

Sublevel 2: Periodization of the exercise is needed. The exercise now has excess recovery load and load of other exercises must be decreased to keep progressing in the exercise. 

Sublevel 3: Now it is necessary to do all of the above. As well as target the specific weak points in the exercise. This is the point where things like specific grip training, band pressing, etc, might now be necessary to increase strength. 

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This is as far as I know on how to progress in an exercise as far as the progressive overloading of the exercise is concerned. Thus, what is clear, is that much time is wasted by doing things that are inappropriate to one's training level in the exercise. Introducing excess exercise variation or bands and chains as a novice. Overfocus on form when past the starter phase with no real breakdown. Etc, are some of the biggest factors besides injury, irregularity, poor recovery management and simple lack of sufficient effort, that can slow or even stall one's progress in an exercise.