Ultra-running isn't good for you: I note that the "Born to Run" guy died of a heart attack in his early 50s while...running.  Marathoners and famous running advocates never seem to live long lives...there is a lesson here for us all, which is that there's nothing Paleolithic about pounding out that much mileage, day after day.  I'm sure it had to be done on occasion, but not as a regular activity.  Without time to heal, stress simply accumulates and damages us.

I feel the same way about Crossfit.  There's nothing wrong with what they do, but doing it every day, or even every other day, is very likely counterproductive.  "Work hard, play hard, challenge yourself, then rest."

JS

It is about the attitude.

Prey fear; predators grin and savour adversity.

I don't think you could call any CrossFitter prey, nor a mountain biker or ultra-runner (all joyfully stressful activities); those low-fat yoghurt eaters who "have" to do their three five mile runs for fear of losing shape, you can.

Paleolithic life very likely involved being both hunter and hunted.  And the stress response is a robust part of any exercise that involves pushing one's limits -- so I suspect that stress after exercise, during which the body should be undergoing compensatory adaptation (which the stress response inhibits), is much more of a problem than stress during exercise.

To that end, if you're exercising out of a sense of duty or obligation, it's unlikely to relieve your stress to the same degree as something playful which you enjoy.  And a life that involves continually counting calories ingested and expended is likely to involve quite a bit of stress.  So I think there's something to the theory, though perhaps not exactly in the way it's presented.

JS

There are some really useful ideas in there. I was expecting it more like "gym addicts are prey … outsiders are predators", but the notion of stressed outdoor running being like prey running for their lives several times a day was an interesting change of perspective.

As people who engage in a paleo lifestyle we aim to ape our hunger/gatherer ancestors, yet persist in making our activity unnecessary or within confines that are nothing to do with that way of life; even those who run outside.

When we're out, are we "hunting"?

My evening walks are to take in the weather, take in horizons and often enjoy the sun going down. I walk slowly, quickly, stressfully uphill, restfully along ridges, tentatively downhill and often end up pretend hunting, tracking deer through our valley. The actions of a predator are to circle more slowly and then burst into a brief period of frenetic activity.

After reading this article, it struck me that I have found an accord with our hunting ancestry. In fact, out once, I burst into sprint entering a new field to find the grazing rabbits scatter but to my absolute surprise, I actually caught one! I let the little fellow go.

Is this down to attitude?

Can the same kind of activity be engaged in as both predator and prey, or is it more a case of get into the wild and chase something as opposed to running around the block several times a day for fear of losing shape, like George Clooney's character in 'Burn After Reading'?