The definition provided is the correct one, of course. As this equilibrium point is unique though, so should the term used to describe it (I prefer the more descriptive Maximal Lactate Steady State, MLSS, as ‘anaerobic’ implies the lack of O2, which isn’t the case, of course).
Two points here: (1) the determination method of this intensity and (2) the range provided above, which is (correctly) so lenient that it is meaningless, unless individually determined (neither point is for this thread/forum, but I just wanted to mention them.)
Provided this intensity (i.e., the “anaerobic” threshold) is accurately determined, this may well be the case. But I am questioning the effectiveness of this training method for the establishment of the mentioned adaptations generally in runners and even more so in a 400 m sprinter. Firstly, because a 400 m sprinter will most likely meet this intensity at the lower end of the %VO2max range mentioned before and quite possibly at an almost pedestrian for him speed (and therefore, I don’t think there would be a problem with the issue raised by Charlie). Secondly, because any speed above this intensity and up to the VO2max level will also bring about these adaptations, since any sub-VO2max intensity will also be positively affected and to an adequate degree for our example sprinter. The latter tactic (i.e., close to VO2max) would be preferable in my opinion, because of time efficiency in terms of the mentioned adaptations and because of the greater contribution to a “more energetic resource to be used at the end of the race for a stronger finish” simply by a higher VO2max level. That is, IF you want to use this kind of training with the latter part of a 400-m race in mind and not other more specific ones (e.g., speed reserve, SE). Although the ‘VO2max’ type training provides other -equally important- benefits and must be present, it is still irrelevant to the pace and physiological demands of the latter part of a 400-m race (i.e., any pace up to VO2max is well below a short sprinter’s race pace -again, I don’t see an intensity conflict here).
Again, please, take the above as simply my way of looking at this specific issue and not a critique towards your methods, of course! Your thoughts are always welcome!
In the interest of keeping this exchange as directed as possible I have no problem in stating that you and I are much closer to agreeing than we are separate in our views regarding this particular topic.