Originally Posted by
Catatonic
I would urge you not to take such a simplistic view of the stages of adaptation.
Justin and AC both started lifting weights with an interest in developing good physiques, and both were doing Crossfit prior to doing linear progression. There's a very good chance that their strength adaptation had a glass ceiling imposed by caloric restriction, while their recovery was distracted by conditioning workouts. Yet they both were able to get strong, but probably not as strong as they could be: its very common for weight-class lifters to experience a short, sudden spike in strength once they start eating to move up a class, breaking long-standing PRs. This is essentially what AC and Justin were doing.
We cannot be certain what adaptations took place, or whether Justin was truly a novice or intermediate by the time he was squatting in the mid 400s: the fact is, he very well could have just been driving his 5RM closer to his 1RM. Its hard to do, but possible, and his description of merely surviving every workout as he approached 500 seems consistent with this.
And let's not forget that strength is not a general adaptation - it is specific to movements, with some carry-over to other movements. Justin was unadapted to the low-bar squat, but the musculature necessary to achieve his squat numbers was likely already there.
Let me word it this way: I believe that Justin both had the structural and neuro-endocrine adaptations consistent with an intermediate lifters, but caloric restriction and - most importantly - lack of specific adaptation to the low-bar squat prevented him from -expressing- this level of adaptation. His rapid progress on linear progression, in a sense, was simply his body playing catch-up, with few hindrances in the way of physical adaptation that would be observed in rank novices.