Mark Allen HR article - alternating anaerobic and aerobic
Before I joined EN, I came across essentially this same article from Mark Allen, where he talks about the value of aerobic training: http://markallenonline.com/maoArticles.aspx?AID=2
In short, he says that he was killing himself for years trying to run fast (and not just fast, but anaerobically fast - like 5 min/mile), but he found himself hitting a wall after a year or so. Then it was recommended that he run strictly in an aerobic HR, never letting his HR get above 155. After a year, his HR of 155 pace was down to 5:20 min/mile.
Then, he goes on to say that you reach a plateau with that, and it's time to go anaerobic again for a time. In the end, his approach seems to be one of alternating periods of purely aerobic training with periods of heavy anaerobic training.
Two things about it stuck with me:
1) It's coming from Mark Allen, who presumably knows a thing or two as compared to half the blow-hards out there on the internet.
2) It straddled the worlds between those who say you have to do a lot of aerobic training, and those who say you have to train fast to run fast.
I came across this article again today, and various questions kept popping into my mind, all centered around trying to answer the one primary question - what is it about that training philosophy that makes it such that we here at EN don't follow it?
Realize I'm not trying to turn training philosophy on its head 
- I'm genuinely curious what part of that training philosophy I'm missing, and I'm assuming I'm missing something because presumably someone here has seen that article and come up with reasons why we we don't subscribe to it.
Does it come back to the fact that Mark is a pro and has all kinds of time to dedicate 20 hours per week for an entire year to aerobic training?
Is it that EN plans actually have sufficient aerobic training included in them (which would then beg the question of whether there's a difference between a specified period of aerobic training vs just having it sprinkled in week after week)?
Is it that Mark mentions specifically anaerobic training (Z6, Z7), where, based on Coggan's power training zones (here), the benefits of things like plasma volume increase, capillarization, stroke volume, etc drop off like a rock as compared to the Z3, Z4 and Z5 workouts we do here at EN, and as a result of this drop off, he has to go back to aerobic to 'fill the void', so to speak? By contrast, the EN plans with their large amounts of TP and VO2Max maybe don't require nearly as much Z1/Z2 aerobic activity (basically, coming back to the ROI argument)?
Obviously, what we do here at EN works, and people have made huge gains - so I'm not trying to argue that at all. But a small part of my brain wonders whether maybe people see such large gains upon starting up with EN because they've done loads of aerobic training prior, so their body is geared up to reap the benefits of fast training (which EN provides) for some time before having to switch back to lower intensity stuff.
(I feel like I should state that I'm full on bought in to the EN training philosophy - it's worked for me so far in the short few months I've been here, there are hundreds of testimonials saying it works, and many people have been here for multiple years - so that provides evidence that it continues to work. Rather, I'm just trying to figure out the 'why' is all)
Comments
I may be wrong on this answer cuz I aint the coach.
However, from what you state in the article about Mark Allen, he is basically engaging in a form of periodization with aerobic/ anaerobic fitness training. As such I'd put out there the coaches do the something in a holistic approach geared to the flavor of your season training plan. Look at a plan, pick one and you can see the progression the ups and downs and breaks between races all this is a form of periodization like Mark Allen uses and it's the same principle with weight training.
So, even when you're busting your arse doing a high % of anaerobic work, your aerobic system is also working and reaping the benefits.
@Scott - So with that being the case (that you never really completely abandon doing aerobic activity), is the reason why the Coggan power zones show virtually no improvement for those physiological factors that Z4/Z5 work shows because you can't maintain anaerobic workouts long enough to really reap the benefits?
The interesting thing is that Mark was saying that in every run, he'd try to get a mile in @ the 5 min/mile pace - it's not like he was walking out the door, crushing it for a mile and then finishing up. There was plenty of aerobic activity before/after that 5 min/mile pace. So that makes me wonder whether part of the benefit he saw was due to physiological benefits that can only be brought about by maintaining a HR well within the aerobic zone for all workouts over an elongated period of time.
MY $.02 cent......I don' t believe that anybody advocates doing one or the other; different philosophies apply diffrent levels of priority and order of stimulous to Anerobic & Aeorobic training efforts...even Arthur Lydiard who is the god father of Long Slow Distance...did intervals.....he just was a very strong proponent of, and advocated building a big Aeorbic baseload of fitness before applying sharpening speed work.....
One thing to keep in mind here...is that EN plans Assume you come into the training with a solid base foundation of fitness....
but like anything else if you have the time...to build a bigger foundation/walls of the house...then do so...before starting to raise your roof......
...but as the EN philosophy of ROI goes...if you are starting from point A with X level of current fitness...and you want to optimize that for an IM at Point B...the most direct/and efficient way is Fast then Far...trying to build volume and raise your Threshold at the same time on a limited time budget (ie that exists for most AGers with a job)...is a recipe for injury or burnout
If you have 22 hours a week to dedicate to additional aerobic volume AND recover...then that may be a different story.
1) do most of your work very easy, do lots of it, and occasionally, go VERY hard (VO2+). Spend very little time training in the "gray area" of Z3.
2) if you don't have the time/lifestyle/motivation to do #1, then spend less time on it, but because you're spending less time, you need to go harder in most/all of your sessions. Some/many people are able to be very, very successful with this philosophy.
This plays out in the MarkAllenOnline/QT2 Systems approach vs. the EN approach, but it also plays out in the Jack Daniels Method / Pete Pfitzinger Method / Arthur Lydiard method vs. the Furman method in marathon training and elsewhere.
Bottom line, if you've got a lot of time, there's definitely benefit to spending tons of volume on your sport. But, because you're spending tons of time on it, you need to do it mostly at a low intensity or you'll fall apart. Hence, the "LSD" thought process.
Most of us are here precisely because we don't have that kind of time (or want to spend the time we have like that), so we look for alternatives. The EN way is an alternative to get you to the start line pretty fit.
I'll leave the debate as to which method is "better" for another day. Just remember, there's nothing magical about going slow. If you only go slow 5-6 hours a week, you won't get better. But if you go slow 18-25 hours a week, you probably will. For some reason, it's always pitched as the magic of going slow, but in reality, it's the magic of doing a lot of work through volume instead of through intensity.
As a side note, there are many people in the marathon world who blame the "intensity craze" of the 80's-90's for the lack of having any decent American marathoners for almost 20 years. Most of those same folks suggest that it was only when American marathoners got back to putting in a ton of miles did they get any good again. Just keep in mind, the planet on which those guys live re: fitness could not be less related to the planet on which we live...