From a press release regarding an as of yet unpublished study conducted over the past 36 years:
Undertaking regular jogging increases the life expectancy of men by 6.2 years and women by 5.6 years, reveals the latest data from the Copenhagen City Heart study presented at the EuroPRevent2012 meeting.
Reviewing the evidence of whether jogging is healthy or hazardous, Peter Schnohr told delegates that the study’s most recent analysis (unpublished) shows that between one and two-and-a-half hours of jogging per week at a “slow or average” pace delivers optimum benefits for longevity. [...]
The debate over jogging first kicked off in the 1970s when middle aged men took an interest in the past-time. “After a few men died while out on a run, various newspapers suggested that jogging might be too strenuous for ordinary middle aged people,” recalled Schnohr.
The press release doesn’t talk about how the study controlled for other health factors. Do joggers live longer than swimmers or cyclists? Did the joggers and non-joggers have otherwise similar health habits (diet, tobacco, etc.)?