NYT: Why Some People Get Fitter Than Others

photo copyright Getty Images/New York Times

http://well.blogs.nytimes.com/2015/04/29/why-some-people-get-fitter-than-others/?hpw&rref=health&action=click&pgtype=Homepage&module=well-region&region=bottom-well&WT.nav=bottom-well&_r=0