Why Rabbits Don't Have to Do Pushups

April 26, 2011

Why Rabbits Don’t Have to Do Pushups! 

 Competency: Vitamin D   Reference:  Amer Jr Cardiology,  

 Ever seen a rabbit doing aerobics?  Pumping iron?  Even seen a deer out jogging to stay in shape?  Are any squirrels doing Tai Chi?   How is it that these animals can stay in great shape without going to the Y?   Of course, the first thought that came to your mind is that these animals don’t have to stay in great shape, just enough to be faster than the slowest member of their type.  As long as I can run faster than you, I’m safe from the bears that are chasing us.  Same with the squirrel.  

But there is a deeper question here that might be more interesting. This is what Dr. Ardestani and his group from Hartford discovered and published.  They took 200 volunteers of all shapes and sizes, all levels of fitness and all ages and found a very interesting linear relationship.  For every level of cardiovascular fitness, Vitamin D levels predicted your being in better shape.  In fact, couch potatoes showed the strongest effect.   There was a marked difference between those with a level of 60 and 20 ng.  This included and was held constant for the amount of time folks spend outdoors.  Exercise buffs are often outdoors, so Vitamin D levels would be higher in them by sun exposure.  This was controlled for.  

This is the second study this column has covered that says the exact same thing.  Our prior review showed that in high school girls fitness measured by the ability to jump, climb, push, run and lift was all predicted in a linear fashion by Vitamin D level. How does D do that?  Fundamentally, D is your stem cell hormone.  It tells every cell in your body to mature into a mature cell.  Immature cells, without adequate Vit. D can’t mature and do their function.  Every tissue in your body (all 1900 cell types we’ve looked at so far) have stem cells and those stem cells respond to D.  Just like plankton in the bottom of the ocean that have been dormant for 10,000 years, when brought to the surface and exposed to light,  make D before they start to divide, our stem cells need D to start the journey to maturity.  (So in winter, with no D, your white blood stem cells don’t mature and you then can’t fight viruses.  So you get the flu)  Same with muscle cells. That means part of deconditioning is not just being a couch potato, but being a couch potato indoors away from the sun.    

The flip side of that is that being a couch potato on vitamin D might just slow down your deconditioning.  That’s what this study says. So that’s why rabbits don’t have to pump iron to stay in shape.  They are outdoors all day long. They are getting their D naturally.  Our hunter-gatherer forebears were outside all day long.  Our great-grandparents who were farmers were outdoors all day long.  And now, we’ve moved indoors, onto the couch and behind the computer screen.  We don’t pump iron, we don’t go to the Y and ….. we at least take our D. 

WWW. What will work for me.  I just had some measurements of my own personal fitness.  It was not a pretty sight.  I’m out of shape.  Rather badly. My mortality risk is higher because my cardiovascular fitness is below average.  But now I understand why D reduces all-cause mortality so significantly.  It plays on every tissue in my body to mature, even my flabby muscles.  As much as they can.  I continue to aim for a level of 60 ng, as that is about what those bunny rabbits, squirrels, deer…..and great grandparents had.  When I first measured my level of D without any supplementation, my level was 7 ng.  Yours is too if you aren’t on a supplement.  So, let's all get in shape with summer coming.  Get outdoors, with some sunblock after 20 minutes, and get in shape.  You the proverbial 40-year-old mother of two with no time to exercise?  I would love to hear how you use your imagination to keep in shape and get outdoors with the kids.

Column by Dr John E Whitcomb, Brookfield Longevity, Brookfield WI