Elite male runners lead the field in the 121st Boston Marathon on Monday, April 17, 2017, in Hopkinton, Mass.
Elite male runners lead the field in the 121st Boston Marathon on Monday, April 17, 2017, in Hopkinton, Mass. Steven Senne AP
Elite male runners lead the field in the 121st Boston Marathon on Monday, April 17, 2017, in Hopkinton, Mass. Steven Senne AP

1 hour of running may add 7 hours to your life

April 19, 2017 12:10 AM