Life-long spontaneous exercise does not prolong lifespan but improves health span in mice http://www.longevityandhealthspan.com/content/2/1/14 http://www.longev

Life-long spontaneous exercise does not prolong lifespan but improves health span in mice http://www.longevityandhealthspan.com/content/2/1/14 http://www.longevityandhealthspan.com/content/2/1/14 Dose of Jogging and Long-Term Mortality : The Copenhagen City Heart Study http://dx.doi.org/10.1016/j.jacc.2014.11.023 http://dx.doi.org/10.1016/j.jacc.2014.11.023 Working up a sweat -- it could save your life http://www.eurekalert.org/pub_releases/2015-04/jcu-wua040215.php http://www.eurekalert.org/pub_releases/2015-04/jcu-wua040215... Lack of exercise kills roughly as many as smoking, study says http://latimesblogs.latimes.com/world_now/2012/07/lack-of-exercise-kills-roughly-as-many-as-smoking-study-says.html http://latimesblogs.latimes.com/world_now/2012/07/lack-of-ex... Every Minute Of Exercise Could Lengthen Your Life Seven Minutes http://commonhealth.wbur.org/2013/03/minutes-exercise-longer-life http://commonhealth.wbur.org/2013/03/minutes-exercise-longer... And so on. There's a lot more out there on exercise and mortality risk as determined from large epidemiological data sets in humans or cause-and-effect animal studies if you care to go look around. One present focus is trying to pin down the dose-response curve, for example. Telomere length, as measured in the study linked here, isn't worth paying much attention to. There are many, many problems with linking average telomere length in white blood cells to specific outcomes in aging. In many ways it is even more of a fuzzy number than, say, BMI or exercise level.