The Exercise Urge
“Whenever I get the urge to exercise, I just lay down till it goes away.” The quote has been variously ascribed to W. C. Fields and former University of Chicago President Robert Hutchins, but whoever uttered these words captured the sentiment of many modern people.
Scads of health benefits have been linked to active exercise, but largely unknown are precisely what molecular changes in body chemistry occur that might provoke such benefits. New work from a group associated with Harvard and Boston University takes a closer look at the underlying chemistry (Science Translational Medicine 2:33 [26 May 2010], 33–37).
These researchers used a sensitive mass-spectrometry-based detection to quantify over 200 small molecules in blood before and after exercise. The chemicals in question aren’t exotic or foreign, just the normal currency of ordinary metabolism.
The robust metabolic profiles generated show striking differences between fit individuals and couch potatoes. Moreover, direct supplementation of cultured muscle cells with combinations of the most affected metabolites actually influences gene expression, which of course is what ultimately underlies the progression of health and disease.
This doesn’t mean that we now understand how the risks for developing certain diseases are linked to whether or not we run a few laps or do hearty push-ups every morning. But it is a starting point for making such mechanistic understandings possible, or for creating diets that enhance performance.
Perhaps the work will even convince us to work up a sweat more often.