An article in The American Journal of Epidemiology reported that sitting and too little exercise can speed aging by as much as eight years. A group of 1,481 women, average age 79, wore motion sensors for one week, after which a white blood cell count was taken. Those that were more sedentary with little exercise proved to have shorter telomeres. Telemeres are caps at the end of our DNA strands. The shorter and more frayed they are the more susceptible a person may be to to heart disease, certain cancers, type 2 diabetes and shorter life expectancy.