Can running can help you live longer?
I'll give you the fact that if you haven't run for a while (or at all), running isn't going to make you feel like you're going to live longer. When I started, it felt like rapid expiration was far more likely. I started running about 3 years ago now. When I did, I could barely run for more than 60 seconds without having to stop to draw breath, and my shins felt like hell the next day. I was out of cardiovascular shape, and I was running very heavy, landing hard in all he wrong places. I did the couch-to-5km plan over a period of 12 weeks, and I haven't stopped since. Looking back, I think managing to run 7km continuously was my breakthrough point. That would take me around 45 minutes then, which is an interesting physiological point in terms of how the different energy systems in your body are engaged.
Though I'm not in a training cycle for any particular event at the moment, I need a short to medium term goal to motivate me when I am running. I need to sign up to events, because I like the challenge, the social side of running and the thrill of the day of the race. I say race, but I am not really racing others - more the target I have set myself. Though it is fun to try and joust with people along the way.
Anyway, I digress. Back to the point. Recent research points to data indicating that regular running can lead to life expectancy gains of 6 years for men and 5 years for women. The study is only reported from a conference, so the data isn't fully available yet. Although we know that exercise is good for us, some caution is needed in interpreting the report. Yet, the potentially promising finding is that you don't have to be an elite or marathon runner in order to reap the benefits. Running one to two and a half hours a week at a slow-to-average pace is enough to deliver the optimal benefits to longevity. That could be as little as 2 x 30 minute runs, that is slow runs, a week.
What is the right pace? Hard to say, but I'd aim for a pace where your breathing is faster, you feel warmer, but you can still hold a conversation. At this pace, your heart and lungs are being stimulated and this will help you in getting fitter. Try talking to yourself (quietly!) as you run every now and again to check your pace. You should be able to get through a sentence comfortably. If you can only manage 3-4 words without having to take a breath, you're probably going faster than you need to.
I know running isn't for everyone, so you might prefer to cycle or swim, or something else. But regular aerobic activity is the key. And it seems like you don't have to be anything like a professional triathlete to add years to your life if you exercise regularly.