“Science is the belief in the ignorance of the experts.” – Richard Feynman

Gettin’ space swole; NASA’s ARED unit.  A directionally accurate (at least) step for astro-bruhs.

This week I’ll be traveling to, and presenting at, the AHS gathering in Berkeley, CA.  This is a very special time for me, as I actually do get to present (which I don’t feel comfortable doing at my own show), and I get to hangout with all of my Paleo-sphere friends free of the looming pressure of putting on the 3-days long, Paleo f(x) extravaganza.  Not bitching mind you — Michelle and I do Paleo f(x) willingly! — it’s just the realities of business operations prevent us from “cutting loose” at a show we host.  

So what will I be speaking about?  Well, essentially I’ll propose a method by which in-mission astronauts can more efficiently, effectively and safely train while in-flight.  Sounds complicated, right? Hardly.  And truthfully speaking, it’s anything but rocket science.

Annnnnd you just knew, at some point, that cliche was bound to be dropped.  Boom!

But seriously, here’s something to chew on: contrary to popular belief, neither Tang nor Teflon were created for or by NASA.  Rather, these technologies existed previously, and were merely co opted by space agency to satisfy mission-specific needs. The success of Tang and Teflon’s association with the space program then propelled their representative “brands” into the public’s consciousness.  In much the same way, the technology and know-how currently exists to prevent one of the most limiting obstacles to prolonged spaceflight — muscle-wasting and bone deterioration (sarcopenia and osteoporosis).  What can be done to curtail in-flight muscle-wasting and bone loss, and how might this knowledge transform training protocols on earth?  I’m not at all playing to hyperbole when I say that this is space exploration’s equivalent to scurvy of the sailing ship day. 

So, back to the question; what can be done to effectively curtail microgravity-induced sarcopenia and osteoporosis?  Well, quite simply, this: intelligent, Efficient Exercise-like programming, coupled with innovative, ARX (Adaptive Resistance eXercise) equipment technology.

Taking a step back for just a moment, we might ask this: is spaceflight “Paleo”?  A rather odd question, and with little in the way of substantive context.  Of course, spaceflight itself is as far from “Paleo” (i.e., the evolutionary/epigenetic crucible in which our species evolved to thrive) as one might imagine.  However, let’s consider for just a moment what must be undertaken to maintain the human animal during prolonged spaceflight.  And, too, let’s consider how this question must be approached.  “What does the human animal require, not just to survive, but to thrive?”  Surviving (and thriving!) during prolonged spaceflight then becomes an extension of the “surviving and thriving under modern conditions” question.  Just an extreme example of the necessity to assess the question through the lens, and with an awareness of, ancestral fitness.  In other words, the answer can only be found if we examine our species’ past.

Rapid (and rampant) muscle wasting and bone deterioration due to microgravity conditions have bedeviled spaceflight since it’s inception; again, much in the same way that scurvy plagued pre-1800’s extended high-seas travel.  And just as with scurvy’s association with lack of fresh citrus (later identified as a lack of vitamin C), spaceflight engineers will eventually come to recognize that the lack of eccentric loading on the human body as the predominant cause of both muscle and bone wasting.  How extreme is the muscle loss and bone deterioration?  In rats, muscle loss of up to 1/3 total mass in some muscle groups in only 10 days is common.  In humans (though apparently no muscle biopsy studies have been conducted), the reduction in the capacity for work after six months in space (using current exercise protocols) can exceed 40 percent, which would temporarily reduce the performance of a returning astronaut to that of an 80-year-old.  And bone deteriorates at a rate of about 2% a month. 

Sending a healthy astronauts into space, only to have them (a) return to earth, or (b) attempt to do colonization work on Mars, feeble as 80 year-olds, is not a viable option.

Serious eccentric exercise is key; simple enough.  But how to pull off this “gravity-dependent phenomena” in zero-gravity conditions?

The addition of an eccentric load in zero-gravity requires outside-of-the-box thinking, of course.  And on first blush, this seems a daunting task.  However, the technology to do so already exists, and (much like Tang and Teflon!), is just (not so) patiently waiting in the wings to be put to use by the space agency.  

Ever important, too, remains the public’s perception of eccentric exercise as “extreme”, “inherently dangerous” and “only for athletes and bodybuilders”.  Nothing could be further from the truth.  In fact, eccentric exercise is absolutely essential in the effective treatment of all “diseases of modernity” (via rapid muscle mass accumulation and correlate retardation of fat deposits and hormonal regulation), preventing the scourge of sarcopenia in the aged, and in preventing osteoporosis.  Proving that the methods and modalities associated with this type of training are safe and effective for in-flight astronauts would do much for the “public relations” of garnering acceptance from the diseased and aged, whose quality of life would greatly benefit from this aspect of safe and effective training.

But let’s for a moment return to NASA’s current answer to the resistance training piece of the in-flight exercise puzzle, the above mentioned (and pictured) ARED platform.  It’s a step in the right direction for sure, but seriously lacking in the all-important eccentric phase of each movement. From NASA’s ARED “Man-in-the-loop” test documentation:

Although the load appears fairly constant over the range of motion, there appears to be some loss of load experienced during the eccentric phases of the movements, especially when the movement of the arm exceeds about 10 inches. These curves suggest that eccentric muscle contractions will be conducted with lower force than concentric contractions. Further studies need to be conducted to verify that ARED eccentric loads are 80-90% of concentric loads.

An eccentric that produces less force than the concentric portion of the movement?  That simply ain’t going to cut it, folks.  And our astronauts deserve better. 

In my presentation, I’ll demonstrate how ARX technology (with miniscule payload as compared to the ARED, by the way), can repeatedly produce force curves like the one below, on any compound movement; independent of gravity.

The above force output graph follows the range of motion in an overhead press in the demonstration clip below:

So following the blue graph, left to right, the first peak at the top of the green band represents the force production on the initial eccentric portion of the movement (the platform is lowering, and I’m attempting to stop it).  The initial valley represents the critical joint angle of the motion (lowest/turn-around position).  The two “mini peaks” at the bottom of the green band represent force production in the concentric portion of the lift (I’m attempting to push the platform away, faster than it’s actually moving).  Notice that the force production in the concentric phase is only 60% (i.e., a 40% drop) of what I produced in the eccentric portion of the movement!  That’s HUGE!  In essence, that amount of force production is what’s not being done by astronauts using the ARED.  

The bottom line is this: using the ARED with deficient eccentric loading, type-II fibers are never adequately taxed, and muscle wasting and bone deterioration will never be adequately reversed.   Unless the eccentric portion of the motion is emphasised in compound exercises during space missions, astronauts will continue to suffer the consequences of sarcopenia and osteoporosis.

The technology exists to do better.

In health, fitness, and ancestral wellness,




  1. This makes a lot of sense to me Keith. Do you have any ideas for creating the ongoing loading we experience just living in gravity? Is it possible for folks in zero gravity to experience none of these effects with sufficient training? I am presuming that these people are in good condition already. Just curious. I always think of the wheel in 2001 and how centrifugal force can approximate gravity in some ways, especially if the turn is big enough.


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