I got a call from a prospective client. The call was about one of the most common
issues that brings us new clients….the results of a recent DEXA scan.
People often become very alarmed when their DEXA results return with
poor scores and their doctor recommends starting bisphosphonates
(medications like Fosamax) to try and reverse their bone loss. This
usually triggers an internet search on treating and preventing
osteoporosis, which invariably uncovers some article about SuperSlow and
its genesis in the Osteoporosis Research Project at the University of
Florida. This in return creates some sort of link to Ultimate Exercise
(or many other such facilities).
I have always been a pretty vocal opponent of DEXA scans because I
feel that they alarm patients (a morbidity) and triggers the urge to do
“something”. That something is usually bisphosphonates, a class of
drugs with some pretty gnarly side-effects. Further, the benefits of
increasing bone mineral density have always been a little oversold by
correlating an absolute increase in bone density with a relative
percentage risk reduction of fractures. Further, literature suggests
that the real correlate for fracture risk is your starting level of bone
mineral density, NOT the level you improve to. To me this has always
suggested that bone density was simply a surrogate marker for fracture
risk. I have always suspected the real marker for risk was muscle mass
and the resultant strength level.
If we look at these images lifted from Skyler Tanner’s post on
bending the aging curve, we must ask ourselves if the sedentary person’s
real risk of a fall and subsequent fracture really dependent on the
bone density of his femur? Or…is the real problem the atrophy that has
occurred in his thigh muscles and the fact that if he gets the least bit
off of his center of gravity he is going down. And when he (or she)
does go down, there is not enough shock absorbing skeletal muscle to
protect that frail femur from snapping in two. If you stuck that frail
bone in the middle of all the muscle in the pictures above or below, do
you think it would stand a much better chance all the way around?
But the situation is actually much better than that. Because, when
you improve the muscle mass the bone mineral density tracks right along
(as does all other organ mass). It used to be thought that the bone
mineral density was increasing because of the forces upon the
bone…strain and stress that could also risk a fracture. But I have seen
too many clients improve bone mineral density without exposure to
dangerous force to believe that. As it turns out the increase in bone
density, as well as other improvements in organ mass, are related to
muscle to organ cross talk mediated by myokines. There is even evidence
that myokine exposure can improve bone density in the complete absence
of stress/strain loading. So when someone tells you that slow cadence,
force-controlled exercise does not sufficiently stress the bone to
improve bone density, you can smile and walk away. As it turns out,
training in this way gives you all of the upside and none of the down
side of the traditional notion of “load-bearing exercise”. What the new
research on myokines is demonstrating is that proper strength exercise
is the most profound public health initiative that we have available too
us. The economic implications of a vibrant and productive aging
populace, as opposed to a debilitated and dependent one is almost too
big to imagine.
This is especially true in light of the collapse of our medical and social entitlement systems.
To get further insight into the issue of muscle-bone cross-talk via myokines, check out the interview linked below:
http://www.nature.com/bonekey/community/2012/05/moving-from-bone-to-muscle-and-back-again-an-interview-with-mark-hamrick/
