A study looking at the workout habits of more than 55,000 individuals for 15 years has concluded that running can reduce a person’s all-cause mortality rate by 30% and cardiovascular mortality rate by 45%. This equated to a difference of about three years of life.
But the really exciting news is that people who ran less than an hour each week showed the same mortality benefits compared to those who ran more than three hours in each week. Note that this is more about running, say, ten minutes every day, than only running once a week for a longer time! You don't have to run fast, either. Those running more slowly (< 6 miles/hour) got the same benefits.
Not running had about the same negative effect on life expectancy as having hypertension.
Around 24% of the participants did some running. The average age was 44.
http://www.futurity.org/even-short-slow-running-can-extend-lifespan/
Lee D, Pate RR, Lavie CJ, Sui X, Church TS, Blair SN. Leisure-Time Running Reduces All-Cause and Cardiovascular Mortality Risk. J Am Coll Cardiol. 2014;64(5):472-481. doi:10.1016/j.jacc.2014.04.058.