High intensity intervals vs Longer, slow, steady runs

After my last post I have been told that I am living in a high-intensity-interval “echo chamber.” In other words, I am like a climate change denier who only seeks out articles arguing that climate change is not occurring, and becomes caught in an "echo chamber" continuously being only fed yet more such articles by social media, search and his circle of friends, and where competing views are screened out.  I am only reading that high-intensity is beneficial, and long-slow marathon training is somehow “old-school” and “ineffectual” and more likely to lead to burnout and over-use injury (see my last post below).  Moreover, when I lead my weekly high-intensity hill repeats or run Wednesday intervals and ask this self-selected group of participants, they all heartily agree that sprinting up a hill at a crazed level of exertion is the ultimate healthy activity.  

Maybe there is a whole world of evidence that sticking to 100% longer, easier, aerobic runs is optimal?   Longer, steady-state runs seem to be what most of my marathon-focused teammates do almost exclusively, most all the time. Maybe they know something I don't?      

So in my effort to break out of my narrow, close-minded gated community, I find another computer, log-in with a different name and seek articles on the merit of longer, steady exercise.  My search delivers an odd assortment of viewpoints --

• The Oatmail comic outrunning "The Blerch"
• The spiritual pursuits of the Marathon Monks, Christian runners, and Sri Chimnoy
• Paeans to deep, metaphysical, transformative powers of long runs 
• A very old book suggesting that Longer runs are more humane 
• This post arguing that cross-fit enthusiasts are wrong to “rubbish" long slow distance training, that high-intensity exercise is MORE likely to cause injury, and that most people are essentially best to stick to long, slow running 
• "Going Slower to get Faster" on the merits of aerobic “base phase” training
• Or similarly "No Substitute for LSD" chronicling the tendency of "adult-onset" athletes to steadily improve until they crash, and then struggle to return because of endless racing and lack of long recovery runs 
• Laundry lists of physiological and mental benefits of long training sessions
• Perhaps most representative is "Steady-state Cardio vs. High-Intensity-Interval Training" which contrasts "Jane" who only does steady-state runs and "Susan" who only does  high intensity workouts. The article goes on to tell us (not exactly a surprise) that the best program is a combination of both -- along with the customary emphasis on the importance of seasonality (periodization)

My quick reaction - 

1. Wow - there are people that do ONLY high intensity training?

Apparently there is this whole world of sedentary Americans whose only exercise is Crossfit and intense treadmill workouts.  My heart cries out - I feel such sympathy for them.  

2. For runners just 10-20% high intensity seems more appropriate 

3. My triathlete teammates scoff at this idea of long, aerobic base training as "just so 1970s" favoring "reverse periodization"

4. Importance of seasonality - Yeah, yeah, yeah,  see  my "off season" post among others below

5. Reading all these long paeans to the spiritual joy of really really long runs is even more boring than really really long runs

6. Ultimately my effort to be open-minded is an abysmal failure.  Alas, the most compelling data point I stumbled across was this article which largely supports my prevailing view (bias).  The US Military(!) -- that same institution that produced the original 1960s era data on the health benefits of long running — has decided to increase the intensity of their troop’s training and reduce the volume of running based on extensive evidence of over-use injuries and troop performance.