I stopped taking that comment remotely seriously when it claimed:

> As a matter of fact, it is a well known and well documented phenomenon in the literature that if you train at close to maximal capacity on the same training regimen for longer than 3 to 4 weeks, you will stop making gains. You'll see big increases the first 3 weeks, and after that, nothing. This is a nervous system effect.

... which most people who have done heavy weight lifting for example can tell you is at best wildly misleading, and at worst, pure, unadulterated bullshit.

To flatten out after 3-4 weeks would take such extreme over-training, at stress levels way beyond what even most high level athletes would normally even able to achieve in training, that it is extremely unrealistic for most people to every experience it. Certainly not "just" by training at something until you feel you can't do any more. At that point most people are not anywhere near a real maximum.

I don't lift to a "training" 1RM (maximum weight I can at any time lift once) every week, much less manage/try to stress myself into a real max. (the reason for distinguishing these, is that it is normal that you can lift up to 10% +/- more in high stress situations like competitions), so maybe what I do don't count in that guys eyes. But I exercise large compound lifts to near failure (that is, until I have good reason to think that I will be unable to complete the next repetition) every workout - 3-4 times a week. So I'll hit my training 5RM, 3RM, 1RM for the various lifts on consecutive weeks. They are reasonably interchangeable. If I feel good enough, I may go for a 1RM to try to set a new personal record even if it's not the "right week".

And see slow but steady improvement for months on end before I shake anything up, and when I do change things, it is mainly for other reasons - some progressions may follow the same program for years. Changing too often does not help - it just confuses you tracking.

Most people are far more likely to run into limitations due to form/technique failures or lack of flexibility that they need to fix than due to any CNS limitations.

Gains do slow down as you get closer to your limits, and you certainly can over-train, but it takes a lot to over-train so badly that you stop seeing gains after 4 weeks even when you massively brutalise major muscle groups on a semi-daily basis. I can't even imagine what you'd need to do to overload your nervous system from typing in that short time-span.