According to a new study out of Iowa State University, every hour that you run adds seven hours to your life. Now, you just blew an hour on running, so I guess your net is six hours, but the authors of the study didn't look at it that way.
And you don't even have to run six-minute miles to increase your lifespan. They say that even if you're just jogging super slowly, you'll still get the health benefits.
There's a cap, though: Running can "only" add about three years to your life.
So if you add seven hours to your life per run, that means you'd need to go on about 3,750 runs to hit the three-year cap...which would mean two one-hour runs per week for 36 years.