Here is another interesting piece to this whole thing. Intensity of exercise appears to be the most important element of preventing age related performance decline. Here is a nice look at this by Clarence Bass:
This is looking at the differences in performance drop-off between sprinters and endurance athletes. Clarence also mentions the longer careers of athletes like throwers, likely do the the frequent recruitment of the largest motor neurons which appears to prevent the death of these motor neurons.
I remember reading this article years ago...not long after I first found Art Devany's work and it obviously influenced my thinking and I think has rattled in my subconscious on things like the Power Bias article.
Now the Evolution and running thread was interesting...obviously the persistence hunting played a huge role in our ancestors strategies. A key point in that discussion was that the human hunters just had to push animals hard enough to overheat the animals. This pace ranged between a sprint and a trot and for any given individual they were not doing this longer hunt all that often.
Just thinking out loud here...not sure if I have too much of a point....just ideas.
I'm pretty comfortable with the notion that strength and power training can produce a residual effect of significant endurance. The opposite is not the case. Again I'm thinking about this from a health and longevity bias...obviously if one wants to be a stud endurance athlete intervals are not going to be the only part of the story.
This may just be rehashing the power bias stuff but...how much mixed modal work should one do to optimize this health/longevity bias? I'd argue for some, but certainly not all. I'd argue for some max strength work for the major movement planes, some sprint work, various intensities and distances, some ballistics like jumping, throwing, hitting and kicking...i think Ross Enamait calls these "power combos"...2-4 movements then a significant rest before the next combo. From there just generally being active and having fun.
Oh! Something else! Shaf mentioned not buying the neuroendocrine element of training as being that big a deal for the training effect. Now I do remember from some of Kramers work that only the muscles worked during a session benefit from the NE response...but the NER is predicated on activation of the largest motor neurons and big movements. I also remember vaguely that the large motor neurons and the attendant fast twitch fibers are quite sensitive to androgen levels...if androgen levels drop...those things die. I need to think about this but it looks like a chicken and egg feed back loop. You need to train the large motor neurons to produce a NER and increase androgen levels AND the large motor neurons are dependant on androgen levels...
Anyway...just had some ideas. Please pick this stuff apart/comment on it.